Merge tag 'topic/drm-misc-2016-02-18' of git://anongit.freedesktop.org/drm-intel into drm-next

Misc stuff all over: - more mode_fixup removal from Carlos, there's another final pile still left. - final bits of vgaswitcheroo from Lukas for apple gmux, we're still discussing an api cleanup patch to make it a bit more abuse-safe as a follow-up - dp aux interface for userspace for tools&tests from Rafael Antognolli - actual interface parts for dma-buf flushing for userspace mmap - few small bits all over - vgaswitcheroo support for apple gmux from Lukas Wunner - checks for ->mode_fixup in non-atomic helpers from Carlos Palminha, plus removing dummy funcs from drivers. Carlos promised to follow up with more, since there's lots more silly dummy functions around. - dma-buf patches from Tiago, except the ioctl itself (that needed a respin to address review from David Herrmann) - encoder mask for atomic from Maarten - bunch of random things all over. * tag 'topic/drm-misc-2016-02-18' of git://anongit.freedesktop.org/drm-intel: (57 commits) drm/udl: Use module_usb_driver drm: fixes crct set_mode when crtc mode_fixup is null. drm/tilcdc: removed optional dummy encoder mode_fixup function. drm/sti: removed optional dummy encoder mode_fixup function. drm/rockchip: removed optional dummy encoder mode_fixup function. drm/qxl: removed optional dummy encoder mode_fixup function. drm/mgag200: removed optional dummy encoder mode_fixup function. drm/msm/mdp: removed optional dummy encoder mode_fixup function. drm/imx: removed optional dummy encoder mode_fixup function. drm/gma500: removed optional dummy encoder mode_fixup function. drm/radeon: removed optional dummy encoder mode_fixup function. drm/cirrus: removed optional dummy encoder mode_fixup function. drm/bochs: removed optional dummy encoder mode_fixup function. drm/ast: removed optional dummy encoder mode_fixup function. drm/amdgpu: removed optional dummy encoder mode_fixup function. drm/exynos: removed optional dummy encoder mode_fixup function. drm/udl: removed optional dummy encoder mode_fixup function. drm/virtio: removed optional dummy encoder mode_fixup function. drm/fb_helper: Use add_one_connector in add_all_connectors. drm/fb_helper: Use correct allocation count for arrays. ...
2016-02-19 10:57:44 +10:00 · 2016-02-19 10:57:44 +10:00 · 08244c0085
--- a/Documentation/DocBook/gpu.tmpl
+++ b/Documentation/DocBook/gpu.tmpl
@ -3422,6 +3422,7 @@ int num_ioctls;</synopsis>
    </sect1>
    <sect1>
      <title>Public constants</title>
+!Finclude/linux/vga_switcheroo.h vga_switcheroo_handler_flags_t
 !Finclude/linux/vga_switcheroo.h vga_switcheroo_client_id
 !Finclude/linux/vga_switcheroo.h vga_switcheroo_state
    </sect1>
@ -3450,6 +3451,10 @@ int num_ioctls;</synopsis>
        <title>Backlight control</title>
 !Pdrivers/platform/x86/apple-gmux.c Backlight control
      </sect2>
+      <sect2>
+        <title>Public functions</title>
+!Iinclude/linux/apple-gmux.h
+      </sect2>
    </sect1>
  </chapter>

--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@ -257,17 +257,15 @@ Access to a dma_buf from the kernel context involves three steps:

   Interface:
      int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
-				   size_t start, size_t len,
 				   enum dma_data_direction direction)

   This allows the exporter to ensure that the memory is actually available for
   cpu access - the exporter might need to allocate or swap-in and pin the
   backing storage. The exporter also needs to ensure that cpu access is
-   coherent for the given range and access direction. The range and access
-   direction can be used by the exporter to optimize the cache flushing, i.e.
-   access outside of the range or with a different direction (read instead of
-   write) might return stale or even bogus data (e.g. when the exporter needs to
-   copy the data to temporary storage).
+   coherent for the access direction. The direction can be used by the exporter
+   to optimize the cache flushing, i.e. access with a different direction (read
+   instead of write) might return stale or even bogus data (e.g. when the
+   exporter needs to copy the data to temporary storage).

   This step might fail, e.g. in oom conditions.

@ -322,14 +320,13 @@ Access to a dma_buf from the kernel context involves three steps:

 3. Finish access

-   When the importer is done accessing the range specified in begin_cpu_access,
-   it needs to announce this to the exporter (to facilitate cache flushing and
-   unpinning of any pinned resources). The result of any dma_buf kmap calls
-   after end_cpu_access is undefined.
+   When the importer is done accessing the CPU, it needs to announce this to
+   the exporter (to facilitate cache flushing and unpinning of any pinned
+   resources). The result of any dma_buf kmap calls after end_cpu_access is
+   undefined.

   Interface:
      void dma_buf_end_cpu_access(struct dma_buf *dma_buf,
-				  size_t start, size_t len,
 				  enum dma_data_direction dir);


@ -353,7 +350,26 @@ Being able to mmap an export dma-buf buffer object has 2 main use-cases:
   handles, too). So it's beneficial to support this in a similar fashion on
   dma-buf to have a good transition path for existing Android userspace.

-   No special interfaces, userspace simply calls mmap on the dma-buf fd.
+   No special interfaces, userspace simply calls mmap on the dma-buf fd, making
+   sure that the cache synchronization ioctl (DMA_BUF_IOCTL_SYNC) is *always*
+   used when the access happens. This is discussed next paragraphs.
+
+   Some systems might need some sort of cache coherency management e.g. when
+   CPU and GPU domains are being accessed through dma-buf at the same time. To
+   circumvent this problem there are begin/end coherency markers, that forward
+   directly to existing dma-buf device drivers vfunc hooks. Userspace can make
+   use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The sequence
+   would be used like following:
+     - mmap dma-buf fd
+     - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
+       to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
+       want (with the new data being consumed by the GPU or say scanout device)
+     - munmap once you don't need the buffer any more
+
+    Therefore, for correctness and optimal performance, systems with the memory
+    cache shared by the GPU and CPU i.e. the "coherent" and also the
+    "incoherent" are always required to use SYNC_START and SYNC_END before and
+    after, respectively, when accessing the mapped address.

 2. Supporting existing mmap interfaces in importers

--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@ -34,6 +34,8 @@
 #include <linux/poll.h>
 #include <linux/reservation.h>

+#include <uapi/linux/dma-buf.h>
+
 static inline int is_dma_buf_file(struct file *);

 struct dma_buf_list {
@ -251,11 +253,54 @@ out:
 	return events;
 }

+static long dma_buf_ioctl(struct file *file,
+			  unsigned int cmd, unsigned long arg)
+{
+	struct dma_buf *dmabuf;
+	struct dma_buf_sync sync;
+	enum dma_data_direction direction;
+
+	dmabuf = file->private_data;
+
+	switch (cmd) {
+	case DMA_BUF_IOCTL_SYNC:
+		if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
+			return -EFAULT;
+
+		if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
+			return -EINVAL;
+
+		switch (sync.flags & DMA_BUF_SYNC_RW) {
+		case DMA_BUF_SYNC_READ:
+			direction = DMA_FROM_DEVICE;
+			break;
+		case DMA_BUF_SYNC_WRITE:
+			direction = DMA_TO_DEVICE;
+			break;
+		case DMA_BUF_SYNC_RW:
+			direction = DMA_BIDIRECTIONAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		if (sync.flags & DMA_BUF_SYNC_END)
+			dma_buf_end_cpu_access(dmabuf, direction);
+		else
+			dma_buf_begin_cpu_access(dmabuf, direction);
+
+		return 0;
+	default:
+		return -ENOTTY;
+	}
+}
+
 static const struct file_operations dma_buf_fops = {
 	.release	= dma_buf_release,
 	.mmap		= dma_buf_mmap_internal,
 	.llseek		= dma_buf_llseek,
 	.poll		= dma_buf_poll,
+	.unlocked_ioctl	= dma_buf_ioctl,
 };

 /*
@ -539,13 +584,11 @@ EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
 * preparations. Coherency is only guaranteed in the specified range for the
 * specified access direction.
 * @dmabuf:	[in]	buffer to prepare cpu access for.
- * @start:	[in]	start of range for cpu access.
- * @len:	[in]	length of range for cpu access.
 * @direction:	[in]	length of range for cpu access.
 *
 * Can return negative error values, returns 0 on success.
 */
-int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
+int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
 			     enum dma_data_direction direction)
 {
 	int ret = 0;
@ -554,8 +597,7 @@ int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
 		return -EINVAL;

 	if (dmabuf->ops->begin_cpu_access)
-		ret = dmabuf->ops->begin_cpu_access(dmabuf, start,
-							len, direction);
+		ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);

 	return ret;
 }
@ -567,19 +609,17 @@ EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
 * actions. Coherency is only guaranteed in the specified range for the
 * specified access direction.
 * @dmabuf:	[in]	buffer to complete cpu access for.
- * @start:	[in]	start of range for cpu access.
- * @len:	[in]	length of range for cpu access.
 * @direction:	[in]	length of range for cpu access.
 *
 * This call must always succeed.
 */
-void dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start, size_t len,
+void dma_buf_end_cpu_access(struct dma_buf *dmabuf,
 			    enum dma_data_direction direction)
 {
 	WARN_ON(!dmabuf);

 	if (dmabuf->ops->end_cpu_access)
-		dmabuf->ops->end_cpu_access(dmabuf, start, len, direction);
+		dmabuf->ops->end_cpu_access(dmabuf, direction);
 }
 EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);

--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@ -25,6 +25,14 @@ config DRM_MIPI_DSI
 	bool
 	depends on DRM

+config DRM_DP_AUX_CHARDEV
+	bool "DRM DP AUX Interface"
+	depends on DRM
+	help
+	  Choose this option to enable a /dev/drm_dp_auxN node that allows to
+	  read and write values to arbitrary DPCD registers on the DP aux
+	  channel.
+
 config DRM_KMS_HELPER
 	tristate
 	depends on DRM
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@ -22,10 +22,13 @@ drm-$(CONFIG_OF) += drm_of.o
 drm-$(CONFIG_AGP) += drm_agpsupport.o

 drm_kms_helper-y := drm_crtc_helper.o drm_dp_helper.o drm_probe_helper.o \
-		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o
+		drm_plane_helper.o drm_dp_mst_topology.o drm_atomic_helper.o \
+		drm_kms_helper_common.o
+
 drm_kms_helper-$(CONFIG_DRM_LOAD_EDID_FIRMWARE) += drm_edid_load.o
 drm_kms_helper-$(CONFIG_DRM_FBDEV_EMULATION) += drm_fb_helper.o
 drm_kms_helper-$(CONFIG_DRM_KMS_CMA_HELPER) += drm_fb_cma_helper.o
+drm_kms_helper-$(CONFIG_DRM_DP_AUX_CHARDEV) += drm_dp_aux_dev.o

 obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o

--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c
@ -552,13 +552,14 @@ static bool amdgpu_atpx_detect(void)
 void amdgpu_register_atpx_handler(void)
 {
 	bool r;
+	enum vga_switcheroo_handler_flags_t handler_flags = 0;

 	/* detect if we have any ATPX + 2 VGA in the system */
 	r = amdgpu_atpx_detect();
 	if (!r)
 		return;

-	vga_switcheroo_register_handler(&amdgpu_atpx_handler);
+	vga_switcheroo_register_handler(&amdgpu_atpx_handler, handler_flags);
 }

 /**
--- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
@ -3624,16 +3624,8 @@ dce_v10_0_ext_dpms(struct drm_encoder *encoder, int mode)

 }

-static bool dce_v10_0_ext_mode_fixup(struct drm_encoder *encoder,
-				    const struct drm_display_mode *mode,
-				    struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static const struct drm_encoder_helper_funcs dce_v10_0_ext_helper_funcs = {
 	.dpms = dce_v10_0_ext_dpms,
-	.mode_fixup = dce_v10_0_ext_mode_fixup,
 	.prepare = dce_v10_0_ext_prepare,
 	.mode_set = dce_v10_0_ext_mode_set,
 	.commit = dce_v10_0_ext_commit,
--- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
@ -3619,16 +3619,8 @@ dce_v11_0_ext_dpms(struct drm_encoder *encoder, int mode)

 }

-static bool dce_v11_0_ext_mode_fixup(struct drm_encoder *encoder,
-				    const struct drm_display_mode *mode,
-				    struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static const struct drm_encoder_helper_funcs dce_v11_0_ext_helper_funcs = {
 	.dpms = dce_v11_0_ext_dpms,
-	.mode_fixup = dce_v11_0_ext_mode_fixup,
 	.prepare = dce_v11_0_ext_prepare,
 	.mode_set = dce_v11_0_ext_mode_set,
 	.commit = dce_v11_0_ext_commit,
--- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
@ -3554,16 +3554,8 @@ dce_v8_0_ext_dpms(struct drm_encoder *encoder, int mode)

 }

-static bool dce_v8_0_ext_mode_fixup(struct drm_encoder *encoder,
-				    const struct drm_display_mode *mode,
-				    struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static const struct drm_encoder_helper_funcs dce_v8_0_ext_helper_funcs = {
 	.dpms = dce_v8_0_ext_dpms,
-	.mode_fixup = dce_v8_0_ext_mode_fixup,
 	.prepare = dce_v8_0_ext_prepare,
 	.mode_set = dce_v8_0_ext_mode_set,
 	.commit = dce_v8_0_ext_commit,
--- a/drivers/gpu/drm/ast/ast_mode.c
+++ b/drivers/gpu/drm/ast/ast_mode.c
@ -710,13 +710,6 @@ static void ast_encoder_dpms(struct drm_encoder *encoder, int mode)

 }

-static bool ast_mode_fixup(struct drm_encoder *encoder,
-			   const struct drm_display_mode *mode,
-			   struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void ast_encoder_mode_set(struct drm_encoder *encoder,
 			       struct drm_display_mode *mode,
 			       struct drm_display_mode *adjusted_mode)
@ -736,7 +729,6 @@ static void ast_encoder_commit(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs ast_enc_helper_funcs = {
 	.dpms = ast_encoder_dpms,
-	.mode_fixup = ast_mode_fixup,
 	.prepare = ast_encoder_prepare,
 	.commit = ast_encoder_commit,
 	.mode_set = ast_encoder_mode_set,
--- a/drivers/gpu/drm/bochs/bochs_kms.c
+++ b/drivers/gpu/drm/bochs/bochs_kms.c
@ -152,13 +152,6 @@ static void bochs_crtc_init(struct drm_device *dev)
 	drm_crtc_helper_add(crtc, &bochs_helper_funcs);
 }

-static bool bochs_encoder_mode_fixup(struct drm_encoder *encoder,
-				     const struct drm_display_mode *mode,
-				     struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void bochs_encoder_mode_set(struct drm_encoder *encoder,
 				   struct drm_display_mode *mode,
 				   struct drm_display_mode *adjusted_mode)
@ -179,7 +172,6 @@ static void bochs_encoder_commit(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs bochs_encoder_helper_funcs = {
 	.dpms = bochs_encoder_dpms,
-	.mode_fixup = bochs_encoder_mode_fixup,
 	.mode_set = bochs_encoder_mode_set,
 	.prepare = bochs_encoder_prepare,
 	.commit = bochs_encoder_commit,
--- a/drivers/gpu/drm/bridge/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/dw-hdmi.c
@ -1391,13 +1391,6 @@ static void dw_hdmi_bridge_mode_set(struct drm_bridge *bridge,
 	mutex_unlock(&hdmi->mutex);
 }

-static bool dw_hdmi_bridge_mode_fixup(struct drm_bridge *bridge,
-				      const struct drm_display_mode *mode,
-				      struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void dw_hdmi_bridge_disable(struct drm_bridge *bridge)
 {
 	struct dw_hdmi *hdmi = bridge->driver_private;
@ -1546,7 +1539,6 @@ static const struct drm_bridge_funcs dw_hdmi_bridge_funcs = {
 	.pre_enable = dw_hdmi_bridge_nop,
 	.post_disable = dw_hdmi_bridge_nop,
 	.mode_set = dw_hdmi_bridge_mode_set,
-	.mode_fixup = dw_hdmi_bridge_mode_fixup,
 };

 static irqreturn_t dw_hdmi_hardirq(int irq, void *dev_id)
--- a/drivers/gpu/drm/cirrus/cirrus_mode.c
+++ b/drivers/gpu/drm/cirrus/cirrus_mode.c
@ -430,14 +430,6 @@ void cirrus_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
 	*blue = cirrus_crtc->lut_b[regno];
 }

-
-static bool cirrus_encoder_mode_fixup(struct drm_encoder *encoder,
-				      const struct drm_display_mode *mode,
-				      struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void cirrus_encoder_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode)
@ -466,7 +458,6 @@ static void cirrus_encoder_destroy(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs cirrus_encoder_helper_funcs = {
 	.dpms = cirrus_encoder_dpms,
-	.mode_fixup = cirrus_encoder_mode_fixup,
 	.mode_set = cirrus_encoder_mode_set,
 	.prepare = cirrus_encoder_prepare,
 	.commit = cirrus_encoder_commit,
--- a/drivers/gpu/drm/drm_atomic_helper.c
+++ b/drivers/gpu/drm/drm_atomic_helper.c
@ -125,6 +125,47 @@ get_current_crtc_for_encoder(struct drm_device *dev,
 	return NULL;
 }

+static void
+set_best_encoder(struct drm_atomic_state *state,
+		 struct drm_connector_state *conn_state,
+		 struct drm_encoder *encoder)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+
+	if (conn_state->best_encoder) {
+		/* Unset the encoder_mask in the old crtc state. */
+		crtc = conn_state->connector->state->crtc;
+
+		/* A NULL crtc is an error here because we should have
+		 *  duplicated a NULL best_encoder when crtc was NULL.
+		 * As an exception restoring duplicated atomic state
+		 * during resume is allowed, so don't warn when
+		 * best_encoder is equal to encoder we intend to set.
+		 */
+		WARN_ON(!crtc && encoder != conn_state->best_encoder);
+		if (crtc) {
+			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
+
+			crtc_state->encoder_mask &=
+				~(1 << drm_encoder_index(conn_state->best_encoder));
+		}
+	}
+
+	if (encoder) {
+		crtc = conn_state->crtc;
+		WARN_ON(!crtc);
+		if (crtc) {
+			crtc_state = drm_atomic_get_existing_crtc_state(state, crtc);
+
+			crtc_state->encoder_mask |=
+				1 << drm_encoder_index(encoder);
+		}
+	}
+
+	conn_state->best_encoder = encoder;
+}
+
 static int
 steal_encoder(struct drm_atomic_state *state,
 	      struct drm_encoder *encoder,
@ -134,7 +175,6 @@ steal_encoder(struct drm_atomic_state *state,
 	struct drm_crtc_state *crtc_state;
 	struct drm_connector *connector;
 	struct drm_connector_state *connector_state;
-	int ret;

 	/*
 	 * We can only steal an encoder coming from a connector, which means we
@ -165,10 +205,10 @@ steal_encoder(struct drm_atomic_state *state,
 		if (IS_ERR(connector_state))
 			return PTR_ERR(connector_state);

-		ret = drm_atomic_set_crtc_for_connector(connector_state, NULL);
-		if (ret)
-			return ret;
-		connector_state->best_encoder = NULL;
+		if (connector_state->best_encoder != encoder)
+			continue;
+
+		set_best_encoder(state, connector_state, NULL);
 	}

 	return 0;
@ -216,7 +256,7 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx)
 				connector->base.id,
 				connector->name);

-		connector_state->best_encoder = NULL;
+		set_best_encoder(state, connector_state, NULL);

 		return 0;
 	}
@ -245,6 +285,8 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx)
 	}

 	if (new_encoder == connector_state->best_encoder) {
+		set_best_encoder(state, connector_state, new_encoder);
+
 		DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] keeps [ENCODER:%d:%s], now on [CRTC:%d:%s]\n",
 				 connector->base.id,
 				 connector->name,
@ -279,7 +321,8 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx)
 	if (WARN_ON(!connector_state->crtc))
 		return -EINVAL;

-	connector_state->best_encoder = new_encoder;
+	set_best_encoder(state, connector_state, new_encoder);
+
 	idx = drm_crtc_index(connector_state->crtc);

 	crtc_state = state->crtc_states[idx];
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@ -1160,6 +1160,29 @@ out_unlock:
 }
 EXPORT_SYMBOL(drm_encoder_init);

+/**
+ * drm_encoder_index - find the index of a registered encoder
+ * @encoder: encoder to find index for
+ *
+ * Given a registered encoder, return the index of that encoder within a DRM
+ * device's list of encoders.
+ */
+unsigned int drm_encoder_index(struct drm_encoder *encoder)
+{
+	unsigned int index = 0;
+	struct drm_encoder *tmp;
+
+	drm_for_each_encoder(tmp, encoder->dev) {
+		if (tmp == encoder)
+			return index;
+
+		index++;
+	}
+
+	BUG();
+}
+EXPORT_SYMBOL(drm_encoder_index);
+
 /**
 * drm_encoder_cleanup - cleans up an initialised encoder
 * @encoder: encoder to cleanup
@ -5714,6 +5737,48 @@ int drm_format_vert_chroma_subsampling(uint32_t format)
 }
 EXPORT_SYMBOL(drm_format_vert_chroma_subsampling);

+/**
+ * drm_format_plane_width - width of the plane given the first plane
+ * @width: width of the first plane
+ * @format: pixel format
+ * @plane: plane index
+ *
+ * Returns:
+ * The width of @plane, given that the width of the first plane is @width.
+ */
+int drm_format_plane_width(int width, uint32_t format, int plane)
+{
+	if (plane >= drm_format_num_planes(format))
+		return 0;
+
+	if (plane == 0)
+		return width;
+
+	return width / drm_format_horz_chroma_subsampling(format);
+}
+EXPORT_SYMBOL(drm_format_plane_width);
+
+/**
+ * drm_format_plane_height - height of the plane given the first plane
+ * @height: height of the first plane
+ * @format: pixel format
+ * @plane: plane index
+ *
+ * Returns:
+ * The height of @plane, given that the height of the first plane is @height.
+ */
+int drm_format_plane_height(int height, uint32_t format, int plane)
+{
+	if (plane >= drm_format_num_planes(format))
+		return 0;
+
+	if (plane == 0)
+		return height;
+
+	return height / drm_format_vert_chroma_subsampling(format);
+}
+EXPORT_SYMBOL(drm_format_plane_height);
+
 /**
 * drm_rotation_simplify() - Try to simplify the rotation
 * @rotation: Rotation to be simplified
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@ -73,9 +73,6 @@
 * &drm_crtc_helper_funcs, struct &drm_encoder_helper_funcs and struct
 * &drm_connector_helper_funcs.
 */
-MODULE_AUTHOR("David Airlie, Jesse Barnes");
-MODULE_DESCRIPTION("DRM KMS helper");
-MODULE_LICENSE("GPL and additional rights");

 /**
 * drm_helper_move_panel_connectors_to_head() - move panels to the front in the
@ -337,16 +334,21 @@ bool drm_crtc_helper_set_mode(struct drm_crtc *crtc,
 		}

 		encoder_funcs = encoder->helper_private;
-		if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
-						      adjusted_mode))) {
-			DRM_DEBUG_KMS("Encoder fixup failed\n");
-			goto done;
+		if (encoder_funcs->mode_fixup) {
+			if (!(ret = encoder_funcs->mode_fixup(encoder, mode,
+							      adjusted_mode))) {
+				DRM_DEBUG_KMS("Encoder fixup failed\n");
+				goto done;
+			}
 		}
 	}

-	if (!(ret = crtc_funcs->mode_fixup(crtc, mode, adjusted_mode))) {
-		DRM_DEBUG_KMS("CRTC fixup failed\n");
-		goto done;
+	if (crtc_funcs->mode_fixup) {
+		if (!(ret = crtc_funcs->mode_fixup(crtc, mode,
+						adjusted_mode))) {
+			DRM_DEBUG_KMS("CRTC fixup failed\n");
+			goto done;
+		}
 	}
 	DRM_DEBUG_KMS("[CRTC:%d:%s]\n", crtc->base.id, crtc->name);

--- a/drivers/gpu/drm/drm_dp_aux_dev.c
+++ b/drivers/gpu/drm/drm_dp_aux_dev.c
@ -0,0 +1,368 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Rafael Antognolli <rafael.antognolli@intel.com>
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <drm/drm_dp_helper.h>
+#include <drm/drm_crtc.h>
+#include <drm/drmP.h>
+
+struct drm_dp_aux_dev {
+	unsigned index;
+	struct drm_dp_aux *aux;
+	struct device *dev;
+	struct kref refcount;
+	atomic_t usecount;
+};
+
+#define DRM_AUX_MINORS	256
+#define AUX_MAX_OFFSET	(1 << 20)
+static DEFINE_IDR(aux_idr);
+static DEFINE_MUTEX(aux_idr_mutex);
+static struct class *drm_dp_aux_dev_class;
+static int drm_dev_major = -1;
+
+static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_minor(unsigned index)
+{
+	struct drm_dp_aux_dev *aux_dev = NULL;
+
+	mutex_lock(&aux_idr_mutex);
+	aux_dev = idr_find(&aux_idr, index);
+	if (!kref_get_unless_zero(&aux_dev->refcount))
+		aux_dev = NULL;
+	mutex_unlock(&aux_idr_mutex);
+
+	return aux_dev;
+}
+
+static struct drm_dp_aux_dev *alloc_drm_dp_aux_dev(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *aux_dev;
+	int index;
+
+	aux_dev = kzalloc(sizeof(*aux_dev), GFP_KERNEL);
+	if (!aux_dev)
+		return ERR_PTR(-ENOMEM);
+	aux_dev->aux = aux;
+	atomic_set(&aux_dev->usecount, 1);
+	kref_init(&aux_dev->refcount);
+
+	mutex_lock(&aux_idr_mutex);
+	index = idr_alloc_cyclic(&aux_idr, aux_dev, 0, DRM_AUX_MINORS,
+				 GFP_KERNEL);
+	mutex_unlock(&aux_idr_mutex);
+	if (index < 0) {
+		kfree(aux_dev);
+		return ERR_PTR(index);
+	}
+	aux_dev->index = index;
+
+	return aux_dev;
+}
+
+static void release_drm_dp_aux_dev(struct kref *ref)
+{
+	struct drm_dp_aux_dev *aux_dev =
+		container_of(ref, struct drm_dp_aux_dev, refcount);
+
+	kfree(aux_dev);
+}
+
+static ssize_t name_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	ssize_t res;
+	struct drm_dp_aux_dev *aux_dev =
+		drm_dp_aux_dev_get_by_minor(MINOR(dev->devt));
+
+	if (!aux_dev)
+		return -ENODEV;
+
+	res = sprintf(buf, "%s\n", aux_dev->aux->name);
+	kref_put(&aux_dev->refcount, release_drm_dp_aux_dev);
+
+	return res;
+}
+static DEVICE_ATTR_RO(name);
+
+static struct attribute *drm_dp_aux_attrs[] = {
+	&dev_attr_name.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(drm_dp_aux);
+
+static int auxdev_open(struct inode *inode, struct file *file)
+{
+	unsigned int minor = iminor(inode);
+	struct drm_dp_aux_dev *aux_dev;
+
+	aux_dev = drm_dp_aux_dev_get_by_minor(minor);
+	if (!aux_dev)
+		return -ENODEV;
+
+	file->private_data = aux_dev;
+	return 0;
+}
+
+static loff_t auxdev_llseek(struct file *file, loff_t offset, int whence)
+{
+	return fixed_size_llseek(file, offset, whence, AUX_MAX_OFFSET);
+}
+
+static ssize_t auxdev_read(struct file *file, char __user *buf, size_t count,
+			   loff_t *offset)
+{
+	size_t bytes_pending, num_bytes_processed = 0;
+	struct drm_dp_aux_dev *aux_dev = file->private_data;
+	ssize_t res = 0;
+
+	if (!atomic_inc_not_zero(&aux_dev->usecount))
+		return -ENODEV;
+
+	bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - (*offset));
+
+	if (!access_ok(VERIFY_WRITE, buf, bytes_pending)) {
+		res = -EFAULT;
+		goto out;
+	}
+
+	while (bytes_pending > 0) {
+		uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES];
+		ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf));
+
+		res = drm_dp_dpcd_read(aux_dev->aux, *offset, localbuf, todo);
+		if (res <= 0) {
+			res = num_bytes_processed ? num_bytes_processed : res;
+			goto out;
+		}
+		if (__copy_to_user(buf + num_bytes_processed, localbuf, res)) {
+			res = num_bytes_processed ?
+				num_bytes_processed : -EFAULT;
+			goto out;
+		}
+		bytes_pending -= res;
+		*offset += res;
+		num_bytes_processed += res;
+		res = num_bytes_processed;
+	}
+
+out:
+	atomic_dec(&aux_dev->usecount);
+	wake_up_atomic_t(&aux_dev->usecount);
+	return res;
+}
+
+static ssize_t auxdev_write(struct file *file, const char __user *buf,
+			    size_t count, loff_t *offset)
+{
+	size_t bytes_pending, num_bytes_processed = 0;
+	struct drm_dp_aux_dev *aux_dev = file->private_data;
+	ssize_t res = 0;
+
+	if (!atomic_inc_not_zero(&aux_dev->usecount))
+		return -ENODEV;
+
+	bytes_pending = min((loff_t)count, AUX_MAX_OFFSET - *offset);
+
+	if (!access_ok(VERIFY_READ, buf, bytes_pending)) {
+		res = -EFAULT;
+		goto out;
+	}
+
+	while (bytes_pending > 0) {
+		uint8_t localbuf[DP_AUX_MAX_PAYLOAD_BYTES];
+		ssize_t todo = min_t(size_t, bytes_pending, sizeof(localbuf));
+
+		if (__copy_from_user(localbuf,
+				     buf + num_bytes_processed, todo)) {
+			res = num_bytes_processed ?
+				num_bytes_processed : -EFAULT;
+			goto out;
+		}
+
+		res = drm_dp_dpcd_write(aux_dev->aux, *offset, localbuf, todo);
+		if (res <= 0) {
+			res = num_bytes_processed ? num_bytes_processed : res;
+			goto out;
+		}
+		bytes_pending -= res;
+		*offset += res;
+		num_bytes_processed += res;
+		res = num_bytes_processed;
+	}
+
+out:
+	atomic_dec(&aux_dev->usecount);
+	wake_up_atomic_t(&aux_dev->usecount);
+	return res;
+}
+
+static int auxdev_release(struct inode *inode, struct file *file)
+{
+	struct drm_dp_aux_dev *aux_dev = file->private_data;
+
+	kref_put(&aux_dev->refcount, release_drm_dp_aux_dev);
+	return 0;
+}
+
+static const struct file_operations auxdev_fops = {
+	.owner		= THIS_MODULE,
+	.llseek		= auxdev_llseek,
+	.read		= auxdev_read,
+	.write		= auxdev_write,
+	.open		= auxdev_open,
+	.release	= auxdev_release,
+};
+
+#define to_auxdev(d) container_of(d, struct drm_dp_aux_dev, aux)
+
+static struct drm_dp_aux_dev *drm_dp_aux_dev_get_by_aux(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *iter, *aux_dev = NULL;
+	int id;
+
+	/* don't increase kref count here because this function should only be
+	 * used by drm_dp_aux_unregister_devnode. Thus, it will always have at
+	 * least one reference - the one that drm_dp_aux_register_devnode
+	 * created
+	 */
+	mutex_lock(&aux_idr_mutex);
+	idr_for_each_entry(&aux_idr, iter, id) {
+		if (iter->aux == aux) {
+			aux_dev = iter;
+			break;
+		}
+	}
+	mutex_unlock(&aux_idr_mutex);
+	return aux_dev;
+}
+
+static int auxdev_wait_atomic_t(atomic_t *p)
+{
+	schedule();
+	return 0;
+}
+/**
+ * drm_dp_aux_unregister_devnode() - unregister a devnode for this aux channel
+ * @aux: DisplayPort AUX channel
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *aux_dev;
+	unsigned int minor;
+
+	aux_dev = drm_dp_aux_dev_get_by_aux(aux);
+	if (!aux_dev) /* attach must have failed */
+		return;
+
+	mutex_lock(&aux_idr_mutex);
+	idr_remove(&aux_idr, aux_dev->index);
+	mutex_unlock(&aux_idr_mutex);
+
+	atomic_dec(&aux_dev->usecount);
+	wait_on_atomic_t(&aux_dev->usecount, auxdev_wait_atomic_t,
+			 TASK_UNINTERRUPTIBLE);
+
+	minor = aux_dev->index;
+	if (aux_dev->dev)
+		device_destroy(drm_dp_aux_dev_class,
+			       MKDEV(drm_dev_major, minor));
+
+	DRM_DEBUG("drm_dp_aux_dev: aux [%s] unregistering\n", aux->name);
+	kref_put(&aux_dev->refcount, release_drm_dp_aux_dev);
+}
+EXPORT_SYMBOL(drm_dp_aux_unregister_devnode);
+
+/**
+ * drm_dp_aux_register_devnode() - register a devnode for this aux channel
+ * @aux: DisplayPort AUX channel
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int drm_dp_aux_register_devnode(struct drm_dp_aux *aux)
+{
+	struct drm_dp_aux_dev *aux_dev;
+	int res;
+
+	aux_dev = alloc_drm_dp_aux_dev(aux);
+	if (IS_ERR(aux_dev))
+		return PTR_ERR(aux_dev);
+
+	aux_dev->dev = device_create(drm_dp_aux_dev_class, aux->dev,
+				     MKDEV(drm_dev_major, aux_dev->index), NULL,
+				     "drm_dp_aux%d", aux_dev->index);
+	if (IS_ERR(aux_dev->dev)) {
+		res = PTR_ERR(aux_dev->dev);
+		aux_dev->dev = NULL;
+		goto error;
+	}
+
+	DRM_DEBUG("drm_dp_aux_dev: aux [%s] registered as minor %d\n",
+		  aux->name, aux_dev->index);
+	return 0;
+error:
+	drm_dp_aux_unregister_devnode(aux);
+	return res;
+}
+EXPORT_SYMBOL(drm_dp_aux_register_devnode);
+
+int drm_dp_aux_dev_init(void)
+{
+	int res;
+
+	drm_dp_aux_dev_class = class_create(THIS_MODULE, "drm_dp_aux_dev");
+	if (IS_ERR(drm_dp_aux_dev_class)) {
+		res = PTR_ERR(drm_dp_aux_dev_class);
+		goto out;
+	}
+	drm_dp_aux_dev_class->dev_groups = drm_dp_aux_groups;
+
+	res = register_chrdev(0, "aux", &auxdev_fops);
+	if (res < 0)
+		goto out;
+	drm_dev_major = res;
+
+	return 0;
+out:
+	class_destroy(drm_dp_aux_dev_class);
+	return res;
+}
+EXPORT_SYMBOL(drm_dp_aux_dev_init);
+
+void drm_dp_aux_dev_exit(void)
+{
+	unregister_chrdev(drm_dev_major, "aux");
+	class_destroy(drm_dp_aux_dev_class);
+}
+EXPORT_SYMBOL(drm_dp_aux_dev_exit);
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@ -28,6 +28,7 @@
 #include <linux/sched.h>
 #include <linux/i2c.h>
 #include <drm/drm_dp_helper.h>
+#include <drm/drm_dp_aux_dev.h>
 #include <drm/drmP.h>

 /**
@ -754,6 +755,8 @@ static const struct i2c_algorithm drm_dp_i2c_algo = {
 */
 int drm_dp_aux_register(struct drm_dp_aux *aux)
 {
+	int ret;
+
 	mutex_init(&aux->hw_mutex);

 	aux->ddc.algo = &drm_dp_i2c_algo;
@ -768,7 +771,17 @@ int drm_dp_aux_register(struct drm_dp_aux *aux)
 	strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
 		sizeof(aux->ddc.name));

-	return i2c_add_adapter(&aux->ddc);
+	ret = drm_dp_aux_register_devnode(aux);
+	if (ret)
+		return ret;
+
+	ret = i2c_add_adapter(&aux->ddc);
+	if (ret) {
+		drm_dp_aux_unregister_devnode(aux);
+		return ret;
+	}
+
+	return 0;
 }
 EXPORT_SYMBOL(drm_dp_aux_register);

@ -778,6 +791,7 @@ EXPORT_SYMBOL(drm_dp_aux_register);
 */
 void drm_dp_aux_unregister(struct drm_dp_aux *aux)
 {
+	drm_dp_aux_unregister_devnode(aux);
 	i2c_del_adapter(&aux->ddc);
 }
 EXPORT_SYMBOL(drm_dp_aux_unregister);
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@ -32,6 +32,7 @@
 #include <linux/hdmi.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
+#include <linux/vga_switcheroo.h>
 #include <drm/drmP.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_displayid.h>
@ -1394,6 +1395,31 @@ struct edid *drm_get_edid(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_get_edid);

+/**
+ * drm_get_edid_switcheroo - get EDID data for a vga_switcheroo output
+ * @connector: connector we're probing
+ * @adapter: I2C adapter to use for DDC
+ *
+ * Wrapper around drm_get_edid() for laptops with dual GPUs using one set of
+ * outputs. The wrapper adds the requisite vga_switcheroo calls to temporarily
+ * switch DDC to the GPU which is retrieving EDID.
+ *
+ * Return: Pointer to valid EDID or %NULL if we couldn't find any.
+ */
+struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
+				     struct i2c_adapter *adapter)
+{
+	struct pci_dev *pdev = connector->dev->pdev;
+	struct edid *edid;
+
+	vga_switcheroo_lock_ddc(pdev);
+	edid = drm_get_edid(connector, adapter);
+	vga_switcheroo_unlock_ddc(pdev);
+
+	return edid;
+}
+EXPORT_SYMBOL(drm_get_edid_switcheroo);
+
 /**
 * drm_edid_duplicate - duplicate an EDID and the extensions
 * @edid: EDID to duplicate
--- a/drivers/gpu/drm/drm_encoder_slave.c
+++ b/drivers/gpu/drm/drm_encoder_slave.c
@ -140,6 +140,9 @@ bool drm_i2c_encoder_mode_fixup(struct drm_encoder *encoder,
 		const struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
 {
+	if (!get_slave_funcs(encoder)->mode_fixup)
+		return true;
+
 	return get_slave_funcs(encoder)->mode_fixup(encoder, mode, adjusted_mode);
 }
 EXPORT_SYMBOL(drm_i2c_encoder_mode_fixup);
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@ -104,21 +104,17 @@ int drm_fb_helper_single_add_all_connectors(struct drm_fb_helper *fb_helper)
 {
 	struct drm_device *dev = fb_helper->dev;
 	struct drm_connector *connector;
-	int i;
+	int i, ret;

 	if (!drm_fbdev_emulation)
 		return 0;

 	mutex_lock(&dev->mode_config.mutex);
 	drm_for_each_connector(connector, dev) {
-		struct drm_fb_helper_connector *fb_helper_connector;
+		ret = drm_fb_helper_add_one_connector(fb_helper, connector);

-		fb_helper_connector = kzalloc(sizeof(struct drm_fb_helper_connector), GFP_KERNEL);
-		if (!fb_helper_connector)
+		if (ret)
 			goto fail;
-
-		fb_helper_connector->connector = connector;
-		fb_helper->connector_info[fb_helper->connector_count++] = fb_helper_connector;
 	}
 	mutex_unlock(&dev->mode_config.mutex);
 	return 0;
@ -130,7 +126,7 @@ fail:
 	fb_helper->connector_count = 0;
 	mutex_unlock(&dev->mode_config.mutex);

-	return -ENOMEM;
+	return ret;
 }
 EXPORT_SYMBOL(drm_fb_helper_single_add_all_connectors);

@ -1989,13 +1985,13 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 	width = dev->mode_config.max_width;
 	height = dev->mode_config.max_height;

-	crtcs = kcalloc(dev->mode_config.num_connector,
+	crtcs = kcalloc(fb_helper->connector_count,
 			sizeof(struct drm_fb_helper_crtc *), GFP_KERNEL);
-	modes = kcalloc(dev->mode_config.num_connector,
+	modes = kcalloc(fb_helper->connector_count,
 			sizeof(struct drm_display_mode *), GFP_KERNEL);
-	offsets = kcalloc(dev->mode_config.num_connector,
+	offsets = kcalloc(fb_helper->connector_count,
 			  sizeof(struct drm_fb_offset), GFP_KERNEL);
-	enabled = kcalloc(dev->mode_config.num_connector,
+	enabled = kcalloc(fb_helper->connector_count,
 			  sizeof(bool), GFP_KERNEL);
 	if (!crtcs || !modes || !enabled || !offsets) {
 		DRM_ERROR("Memory allocation failed\n");
@ -2009,9 +2005,9 @@ static void drm_setup_crtcs(struct drm_fb_helper *fb_helper)
 	      fb_helper->funcs->initial_config(fb_helper, crtcs, modes,
 					       offsets,
 					       enabled, width, height))) {
-		memset(modes, 0, dev->mode_config.num_connector*sizeof(modes[0]));
-		memset(crtcs, 0, dev->mode_config.num_connector*sizeof(crtcs[0]));
-		memset(offsets, 0, dev->mode_config.num_connector*sizeof(offsets[0]));
+		memset(modes, 0, fb_helper->connector_count*sizeof(modes[0]));
+		memset(crtcs, 0, fb_helper->connector_count*sizeof(crtcs[0]));
+		memset(offsets, 0, fb_helper->connector_count*sizeof(offsets[0]));

 		if (!drm_target_cloned(fb_helper, modes, offsets,
 				       enabled, width, height) &&
@ -2196,9 +2192,9 @@ EXPORT_SYMBOL(drm_fb_helper_hotplug_event);
 * but the module doesn't depend on any fb console symbols.  At least
 * attempt to load fbcon to avoid leaving the system without a usable console.
 */
-#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
-static int __init drm_fb_helper_modinit(void)
+int __init drm_fb_helper_modinit(void)
 {
+#if defined(CONFIG_FRAMEBUFFER_CONSOLE_MODULE) && !defined(CONFIG_EXPERT)
 	const char *name = "fbcon";
 	struct module *fbcon;

@ -2208,8 +2204,7 @@ static int __init drm_fb_helper_modinit(void)

 	if (!fbcon)
 		request_module_nowait(name);
+#endif
 	return 0;
 }
-
-module_init(drm_fb_helper_modinit);
-#endif
+EXPORT_SYMBOL(drm_fb_helper_modinit);
--- a/drivers/gpu/drm/drm_kms_helper_common.c
+++ b/drivers/gpu/drm/drm_kms_helper_common.c
@ -0,0 +1,60 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Rafael Antognolli <rafael.antognolli@intel.com>
+ *
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_fb_helper.h>
+#include <drm/drm_dp_aux_dev.h>
+
+MODULE_AUTHOR("David Airlie, Jesse Barnes");
+MODULE_DESCRIPTION("DRM KMS helper");
+MODULE_LICENSE("GPL and additional rights");
+
+static int __init drm_kms_helper_init(void)
+{
+	int ret;
+
+	/* Call init functions from specific kms helpers here */
+	ret = drm_fb_helper_modinit();
+	if (ret < 0)
+		goto out;
+
+	ret = drm_dp_aux_dev_init();
+	if (ret < 0)
+		goto out;
+
+out:
+	return ret;
+}
+
+static void __exit drm_kms_helper_exit(void)
+{
+	/* Call exit functions from specific kms helpers here */
+	drm_dp_aux_dev_exit();
+}
+
+module_init(drm_kms_helper_init);
+module_exit(drm_kms_helper_exit);
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@ -1371,8 +1371,7 @@ bool drm_mode_parse_command_line_for_connector(const char *mode_option,
 	}
 done:
 	if (i >= 0) {
-		printk(KERN_WARNING
-			"parse error at position %i in video mode '%s'\n",
+		pr_warn("[drm] parse error at position %i in video mode '%s'\n",
 			i, name);
 		mode->specified = false;
 		return false;
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@ -329,7 +329,7 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
 * drm_gem_prime_export - helper library implementation of the export callback
 * @dev: drm_device to export from
 * @obj: GEM object to export
- * @flags: flags like DRM_CLOEXEC
+ * @flags: flags like DRM_CLOEXEC and DRM_RDWR
 *
 * This is the implementation of the gem_prime_export functions for GEM drivers
 * using the PRIME helpers.
@ -628,7 +628,6 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 				 struct drm_file *file_priv)
 {
 	struct drm_prime_handle *args = data;
-	uint32_t flags;

 	if (!drm_core_check_feature(dev, DRIVER_PRIME))
 		return -EINVAL;
@ -637,14 +636,11 @@ int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
 		return -ENOSYS;

 	/* check flags are valid */
-	if (args->flags & ~DRM_CLOEXEC)
+	if (args->flags & ~(DRM_CLOEXEC | DRM_RDWR))
 		return -EINVAL;

-	/* we only want to pass DRM_CLOEXEC which is == O_CLOEXEC */
-	flags = args->flags & DRM_CLOEXEC;
-
 	return dev->driver->prime_handle_to_fd(dev, file_priv,
-			args->handle, flags, &args->fd);
+			args->handle, args->flags, &args->fd);
 }

 int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
--- a/drivers/gpu/drm/exynos/exynos_dp_core.c
+++ b/drivers/gpu/drm/exynos/exynos_dp_core.c
@ -1155,13 +1155,6 @@ static int exynos_dp_create_connector(struct drm_encoder *encoder)
 	return 0;
 }

-static bool exynos_dp_mode_fixup(struct drm_encoder *encoder,
-				 const struct drm_display_mode *mode,
-				 struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void exynos_dp_mode_set(struct drm_encoder *encoder,
 			       struct drm_display_mode *mode,
 			       struct drm_display_mode *adjusted_mode)
@ -1177,7 +1170,6 @@ static void exynos_dp_disable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs exynos_dp_encoder_helper_funcs = {
-	.mode_fixup = exynos_dp_mode_fixup,
 	.mode_set = exynos_dp_mode_set,
 	.enable = exynos_dp_enable,
 	.disable = exynos_dp_disable,
--- a/drivers/gpu/drm/exynos/exynos_drm_dpi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dpi.c
@ -128,13 +128,6 @@ static int exynos_dpi_create_connector(struct drm_encoder *encoder)
 	return 0;
 }

-static bool exynos_dpi_mode_fixup(struct drm_encoder *encoder,
-				  const struct drm_display_mode *mode,
-				  struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void exynos_dpi_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode)
@ -162,7 +155,6 @@ static void exynos_dpi_disable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs exynos_dpi_encoder_helper_funcs = {
-	.mode_fixup = exynos_dpi_mode_fixup,
 	.mode_set = exynos_dpi_mode_set,
 	.enable = exynos_dpi_enable,
 	.disable = exynos_dpi_disable,
--- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
@ -1597,13 +1597,6 @@ static int exynos_dsi_create_connector(struct drm_encoder *encoder)
 	return 0;
 }

-static bool exynos_dsi_mode_fixup(struct drm_encoder *encoder,
-				  const struct drm_display_mode *mode,
-				  struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void exynos_dsi_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode)
@ -1623,7 +1616,6 @@ static void exynos_dsi_mode_set(struct drm_encoder *encoder,
 }

 static const struct drm_encoder_helper_funcs exynos_dsi_encoder_helper_funcs = {
-	.mode_fixup = exynos_dsi_mode_fixup,
 	.mode_set = exynos_dsi_mode_set,
 	.enable = exynos_dsi_enable,
 	.disable = exynos_dsi_disable,
--- a/drivers/gpu/drm/exynos/exynos_drm_vidi.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_vidi.c
@ -410,13 +410,6 @@ static int vidi_create_connector(struct drm_encoder *encoder)
 	return 0;
 }

-static bool exynos_vidi_mode_fixup(struct drm_encoder *encoder,
-				 const struct drm_display_mode *mode,
-				 struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void exynos_vidi_mode_set(struct drm_encoder *encoder,
 			       struct drm_display_mode *mode,
 			       struct drm_display_mode *adjusted_mode)
@ -432,7 +425,6 @@ static void exynos_vidi_disable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs exynos_vidi_encoder_helper_funcs = {
-	.mode_fixup = exynos_vidi_mode_fixup,
 	.mode_set = exynos_vidi_mode_set,
 	.enable = exynos_vidi_enable,
 	.disable = exynos_vidi_disable,
--- a/drivers/gpu/drm/gma500/cdv_intel_crt.c
+++ b/drivers/gpu/drm/gma500/cdv_intel_crt.c
@ -217,7 +217,6 @@ static int cdv_intel_crt_set_property(struct drm_connector *connector,

 static const struct drm_encoder_helper_funcs cdv_intel_crt_helper_funcs = {
 	.dpms = cdv_intel_crt_dpms,
-	.mode_fixup = gma_encoder_mode_fixup,
 	.prepare = gma_encoder_prepare,
 	.commit = gma_encoder_commit,
 	.mode_set = cdv_intel_crt_mode_set,
--- a/drivers/gpu/drm/gma500/cdv_intel_hdmi.c
+++ b/drivers/gpu/drm/gma500/cdv_intel_hdmi.c
@ -255,7 +255,6 @@ static void cdv_hdmi_destroy(struct drm_connector *connector)

 static const struct drm_encoder_helper_funcs cdv_hdmi_helper_funcs = {
 	.dpms = cdv_hdmi_dpms,
-	.mode_fixup = gma_encoder_mode_fixup,
 	.prepare = gma_encoder_prepare,
 	.mode_set = cdv_hdmi_mode_set,
 	.commit = gma_encoder_commit,
--- a/drivers/gpu/drm/gma500/gma_display.c
+++ b/drivers/gpu/drm/gma500/gma_display.c
@ -478,13 +478,6 @@ int gma_crtc_cursor_move(struct drm_crtc *crtc, int x, int y)
 	return 0;
 }

-bool gma_encoder_mode_fixup(struct drm_encoder *encoder,
-			    const struct drm_display_mode *mode,
-			    struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 bool gma_crtc_mode_fixup(struct drm_crtc *crtc,
 			 const struct drm_display_mode *mode,
 			 struct drm_display_mode *adjusted_mode)
--- a/drivers/gpu/drm/gma500/gma_display.h
+++ b/drivers/gpu/drm/gma500/gma_display.h
@ -90,9 +90,6 @@ extern void gma_crtc_restore(struct drm_crtc *crtc);
 extern void gma_encoder_prepare(struct drm_encoder *encoder);
 extern void gma_encoder_commit(struct drm_encoder *encoder);
 extern void gma_encoder_destroy(struct drm_encoder *encoder);
-extern bool gma_encoder_mode_fixup(struct drm_encoder *encoder,
-				   const struct drm_display_mode *mode,
-				   struct drm_display_mode *adjusted_mode);

 /* Common clock related functions */
 extern const struct gma_limit_t *gma_limit(struct drm_crtc *crtc, int refclk);
--- a/drivers/gpu/drm/gma500/intel_gmbus.c
+++ b/drivers/gpu/drm/gma500/intel_gmbus.c
@ -436,7 +436,7 @@ int gma_intel_setup_gmbus(struct drm_device *dev)
 	return 0;

 err:
-	while (--i) {
+	while (i--) {
 		struct intel_gmbus *bus = &dev_priv->gmbus[i];
 		i2c_del_adapter(&bus->adapter);
 	}
--- a/drivers/gpu/drm/gma500/oaktrail_hdmi.c
+++ b/drivers/gpu/drm/gma500/oaktrail_hdmi.c
@ -601,7 +601,6 @@ static void oaktrail_hdmi_destroy(struct drm_connector *connector)

 static const struct drm_encoder_helper_funcs oaktrail_hdmi_helper_funcs = {
 	.dpms = oaktrail_hdmi_dpms,
-	.mode_fixup = gma_encoder_mode_fixup,
 	.prepare = gma_encoder_prepare,
 	.mode_set = oaktrail_hdmi_mode_set,
 	.commit = gma_encoder_commit,
--- a/drivers/gpu/drm/i2c/ch7006_drv.c
+++ b/drivers/gpu/drm/i2c/ch7006_drv.c
@ -253,6 +253,8 @@ static int ch7006_encoder_create_resources(struct drm_encoder *encoder,
 	drm_mode_create_tv_properties(dev, NUM_TV_NORMS, ch7006_tv_norm_names);

 	priv->scale_property = drm_property_create_range(dev, 0, "scale", 0, 2);
+	if (!priv->scale_property)
+		return -ENOMEM;

 	drm_object_attach_property(&connector->base, conf->tv_select_subconnector_property,
 				      priv->select_subconnector);
--- a/drivers/gpu/drm/i2c/sil164_drv.c
+++ b/drivers/gpu/drm/i2c/sil164_drv.c
@ -252,14 +252,6 @@ sil164_encoder_restore(struct drm_encoder *encoder)
 				     priv->saved_slave_state);
 }

-static bool
-sil164_encoder_mode_fixup(struct drm_encoder *encoder,
-			  const struct drm_display_mode *mode,
-			  struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static int
 sil164_encoder_mode_valid(struct drm_encoder *encoder,
 			  struct drm_display_mode *mode)
@ -347,7 +339,6 @@ static const struct drm_encoder_slave_funcs sil164_encoder_funcs = {
 	.dpms = sil164_encoder_dpms,
 	.save = sil164_encoder_save,
 	.restore = sil164_encoder_restore,
-	.mode_fixup = sil164_encoder_mode_fixup,
 	.mode_valid = sil164_encoder_mode_valid,
 	.mode_set = sil164_encoder_mode_set,
 	.detect = sil164_encoder_detect,
--- a/drivers/gpu/drm/i2c/tda998x_drv.c
+++ b/drivers/gpu/drm/i2c/tda998x_drv.c
@ -856,14 +856,6 @@ static void tda998x_encoder_dpms(struct drm_encoder *encoder, int mode)
 	priv->dpms = mode;
 }

-static bool
-tda998x_encoder_mode_fixup(struct drm_encoder *encoder,
-			  const struct drm_display_mode *mode,
-			  struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static int tda998x_connector_mode_valid(struct drm_connector *connector,
 					struct drm_display_mode *mode)
 {
@ -1343,7 +1335,6 @@ static void tda998x_encoder_commit(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs tda998x_encoder_helper_funcs = {
 	.dpms = tda998x_encoder_dpms,
-	.mode_fixup = tda998x_encoder_mode_fixup,
 	.prepare = tda998x_encoder_prepare,
 	.commit = tda998x_encoder_commit,
 	.mode_set = tda998x_encoder_mode_set,
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@ -35,9 +35,12 @@
 #include "i915_trace.h"
 #include "intel_drv.h"

+#include <linux/apple-gmux.h>
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/vgaarb.h>
+#include <linux/vga_switcheroo.h>
 #include <drm/drm_crtc_helper.h>

 static struct drm_driver driver;
@ -969,6 +972,15 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (PCI_FUNC(pdev->devfn))
 		return -ENODEV;

+	/*
+	 * apple-gmux is needed on dual GPU MacBook Pro
+	 * to probe the panel if we're the inactive GPU.
+	 */
+	if (IS_ENABLED(CONFIG_VGA_ARB) && IS_ENABLED(CONFIG_VGA_SWITCHEROO) &&
+	    apple_gmux_present() && pdev != vga_default_device() &&
+	    !vga_switcheroo_handler_flags())
+		return -EPROBE_DEFER;
+
 	return drm_get_pci_dev(pdev, ent, &driver);
 }

--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@ -193,10 +193,26 @@ static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_n

 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
 {
-	return -EINVAL;
+	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
+	int ret;
+
+	if (obj->base.size < vma->vm_end - vma->vm_start)
+		return -EINVAL;
+
+	if (!obj->base.filp)
+		return -ENODEV;
+
+	ret = obj->base.filp->f_op->mmap(obj->base.filp, vma);
+	if (ret)
+		return ret;
+
+	fput(vma->vm_file);
+	vma->vm_file = get_file(obj->base.filp);
+
+	return 0;
 }

-static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
+static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	struct drm_device *dev = obj->base.dev;
@ -212,6 +228,27 @@ static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size
 	return ret;
 }

+static void i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
+{
+	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
+	struct drm_device *dev = obj->base.dev;
+	struct drm_i915_private *dev_priv = to_i915(dev);
+	bool was_interruptible;
+	int ret;
+
+	mutex_lock(&dev->struct_mutex);
+	was_interruptible = dev_priv->mm.interruptible;
+	dev_priv->mm.interruptible = false;
+
+	ret = i915_gem_object_set_to_gtt_domain(obj, false);
+
+	dev_priv->mm.interruptible = was_interruptible;
+	mutex_unlock(&dev->struct_mutex);
+
+	if (unlikely(ret))
+		DRM_ERROR("unable to flush buffer following CPU access; rendering may be corrupt\n");
+}
+
 static const struct dma_buf_ops i915_dmabuf_ops =  {
 	.map_dma_buf = i915_gem_map_dma_buf,
 	.unmap_dma_buf = i915_gem_unmap_dma_buf,
@ -224,6 +261,7 @@ static const struct dma_buf_ops i915_dmabuf_ops =  {
 	.vmap = i915_gem_dmabuf_vmap,
 	.vunmap = i915_gem_dmabuf_vunmap,
 	.begin_cpu_access = i915_gem_begin_cpu_access,
+	.end_cpu_access = i915_gem_end_cpu_access,
 };

 struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@ -10521,7 +10521,6 @@ retry:
 	}

 	connector_state->crtc = crtc;
-	connector_state->best_encoder = &intel_encoder->base;

 	crtc_state = intel_atomic_get_crtc_state(state, intel_crtc);
 	if (IS_ERR(crtc_state)) {
@ -10617,7 +10616,6 @@ void intel_release_load_detect_pipe(struct drm_connector *connector,
 		if (IS_ERR(crtc_state))
 			goto fail;

-		connector_state->best_encoder = NULL;
 		connector_state->crtc = NULL;

 		crtc_state->base.enable = crtc_state->base.active = false;
@ -15593,6 +15591,7 @@ static void intel_sanitize_crtc(struct intel_crtc *crtc)
 		crtc->base.state->active = crtc->active;
 		crtc->base.enabled = crtc->active;
 		crtc->base.state->connector_mask = 0;
+		crtc->base.state->encoder_mask = 0;

 		/* Because we only establish the connector -> encoder ->
 		 * crtc links if something is active, this means the
@ -15832,6 +15831,8 @@ static void intel_modeset_readout_hw_state(struct drm_device *dev)
 				 */
 				encoder->base.crtc->state->connector_mask |=
 					1 << drm_connector_index(&connector->base);
+				encoder->base.crtc->state->encoder_mask |=
+					1 << drm_encoder_index(&encoder->base);
 			}

 		} else {
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@ -1188,7 +1188,6 @@ intel_dp_aux_fini(struct intel_dp *intel_dp)
 static int
 intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
 {
-	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 	struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
 	enum port port = intel_dig_port->port;
 	int ret;
@ -1199,7 +1198,7 @@ intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
 	if (!intel_dp->aux.name)
 		return -ENOMEM;

-	intel_dp->aux.dev = dev->dev;
+	intel_dp->aux.dev = connector->base.kdev;
 	intel_dp->aux.transfer = intel_dp_aux_transfer;

 	DRM_DEBUG_KMS("registering %s bus for %s\n",
@ -1214,16 +1213,6 @@ intel_dp_aux_init(struct intel_dp *intel_dp, struct intel_connector *connector)
 		return ret;
 	}

-	ret = sysfs_create_link(&connector->base.kdev->kobj,
-				&intel_dp->aux.ddc.dev.kobj,
-				intel_dp->aux.ddc.dev.kobj.name);
-	if (ret < 0) {
-		DRM_ERROR("sysfs_create_link() for %s failed (%d)\n",
-			  intel_dp->aux.name, ret);
-		intel_dp_aux_fini(intel_dp);
-		return ret;
-	}
-
 	return 0;
 }

@ -1232,9 +1221,7 @@ intel_dp_connector_unregister(struct intel_connector *intel_connector)
 {
 	struct intel_dp *intel_dp = intel_attached_dp(&intel_connector->base);

-	if (!intel_connector->mst_port)
-		sysfs_remove_link(&intel_connector->base.kdev->kobj,
-				  intel_dp->aux.ddc.dev.kobj.name);
+	intel_dp_aux_fini(intel_dp);
 	intel_connector_unregister(intel_connector);
 }

@ -4868,7 +4855,6 @@ void intel_dp_encoder_destroy(struct drm_encoder *encoder)
 	struct intel_digital_port *intel_dig_port = enc_to_dig_port(encoder);
 	struct intel_dp *intel_dp = &intel_dig_port->dp;

-	intel_dp_aux_fini(intel_dp);
 	intel_dp_mst_encoder_cleanup(intel_dig_port);
 	if (is_edp(intel_dp)) {
 		cancel_delayed_work_sync(&intel_dp->panel_vdd_work);
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@ -31,6 +31,7 @@
 #include <linux/dmi.h>
 #include <linux/i2c.h>
 #include <linux/slab.h>
+#include <linux/vga_switcheroo.h>
 #include <drm/drmP.h>
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
@ -1080,7 +1081,12 @@ void intel_lvds_init(struct drm_device *dev)
 	 * preferred mode is the right one.
 	 */
 	mutex_lock(&dev->mode_config.mutex);
-	edid = drm_get_edid(connector, intel_gmbus_get_adapter(dev_priv, pin));
+	if (vga_switcheroo_handler_flags() & VGA_SWITCHEROO_CAN_SWITCH_DDC)
+		edid = drm_get_edid_switcheroo(connector,
+				    intel_gmbus_get_adapter(dev_priv, pin));
+	else
+		edid = drm_get_edid(connector,
+				    intel_gmbus_get_adapter(dev_priv, pin));
 	if (edid) {
 		if (drm_add_edid_modes(connector, edid)) {
 			drm_mode_connector_update_edid_property(connector,
--- a/drivers/gpu/drm/imx/dw_hdmi-imx.c
+++ b/drivers/gpu/drm/imx/dw_hdmi-imx.c
@ -109,13 +109,6 @@ static void dw_hdmi_imx_encoder_disable(struct drm_encoder *encoder)
 {
 }

-static bool dw_hdmi_imx_encoder_mode_fixup(struct drm_encoder *encoder,
-					   const struct drm_display_mode *mode,
-					   struct drm_display_mode *adj_mode)
-{
-	return true;
-}
-
 static void dw_hdmi_imx_encoder_mode_set(struct drm_encoder *encoder,
 					 struct drm_display_mode *mode,
 					 struct drm_display_mode *adj_mode)
@ -138,7 +131,6 @@ static void dw_hdmi_imx_encoder_prepare(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs dw_hdmi_imx_encoder_helper_funcs = {
-	.mode_fixup = dw_hdmi_imx_encoder_mode_fixup,
 	.mode_set   = dw_hdmi_imx_encoder_mode_set,
 	.prepare    = dw_hdmi_imx_encoder_prepare,
 	.commit     = dw_hdmi_imx_encoder_commit,
--- a/drivers/gpu/drm/imx/imx-ldb.c
+++ b/drivers/gpu/drm/imx/imx-ldb.c
@ -139,13 +139,6 @@ static void imx_ldb_encoder_dpms(struct drm_encoder *encoder, int mode)
 {
 }

-static bool imx_ldb_encoder_mode_fixup(struct drm_encoder *encoder,
-			   const struct drm_display_mode *mode,
-			   struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void imx_ldb_set_clock(struct imx_ldb *ldb, int mux, int chno,
 		unsigned long serial_clk, unsigned long di_clk)
 {
@ -376,7 +369,6 @@ static const struct drm_encoder_funcs imx_ldb_encoder_funcs = {

 static const struct drm_encoder_helper_funcs imx_ldb_encoder_helper_funcs = {
 	.dpms = imx_ldb_encoder_dpms,
-	.mode_fixup = imx_ldb_encoder_mode_fixup,
 	.prepare = imx_ldb_encoder_prepare,
 	.commit = imx_ldb_encoder_commit,
 	.mode_set = imx_ldb_encoder_mode_set,
--- a/drivers/gpu/drm/imx/imx-tve.c
+++ b/drivers/gpu/drm/imx/imx-tve.c
@ -286,13 +286,6 @@ static void imx_tve_encoder_dpms(struct drm_encoder *encoder, int mode)
 		dev_err(tve->dev, "failed to disable TVOUT: %d\n", ret);
 }

-static bool imx_tve_encoder_mode_fixup(struct drm_encoder *encoder,
-				       const struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void imx_tve_encoder_prepare(struct drm_encoder *encoder)
 {
 	struct imx_tve *tve = enc_to_tve(encoder);
@ -379,7 +372,6 @@ static const struct drm_encoder_funcs imx_tve_encoder_funcs = {

 static const struct drm_encoder_helper_funcs imx_tve_encoder_helper_funcs = {
 	.dpms = imx_tve_encoder_dpms,
-	.mode_fixup = imx_tve_encoder_mode_fixup,
 	.prepare = imx_tve_encoder_prepare,
 	.mode_set = imx_tve_encoder_mode_set,
 	.commit = imx_tve_encoder_commit,
--- a/drivers/gpu/drm/imx/parallel-display.c
+++ b/drivers/gpu/drm/imx/parallel-display.c
@ -112,13 +112,6 @@ static void imx_pd_encoder_dpms(struct drm_encoder *encoder, int mode)
 		drm_panel_enable(imxpd->panel);
 }

-static bool imx_pd_encoder_mode_fixup(struct drm_encoder *encoder,
-			   const struct drm_display_mode *mode,
-			   struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void imx_pd_encoder_prepare(struct drm_encoder *encoder)
 {
 	struct imx_parallel_display *imxpd = enc_to_imxpd(encoder);
@ -166,7 +159,6 @@ static const struct drm_encoder_funcs imx_pd_encoder_funcs = {

 static const struct drm_encoder_helper_funcs imx_pd_encoder_helper_funcs = {
 	.dpms = imx_pd_encoder_dpms,
-	.mode_fixup = imx_pd_encoder_mode_fixup,
 	.prepare = imx_pd_encoder_prepare,
 	.commit = imx_pd_encoder_commit,
 	.mode_set = imx_pd_encoder_mode_set,
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@ -1479,13 +1479,6 @@ void mga_crtc_fb_gamma_get(struct drm_crtc *crtc, u16 *red, u16 *green,
 * These functions are analagous to those in the CRTC code, but are intended
 * to handle any encoder-specific limitations
 */
-static bool mga_encoder_mode_fixup(struct drm_encoder *encoder,
-				   const struct drm_display_mode *mode,
-				   struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void mga_encoder_mode_set(struct drm_encoder *encoder,
 				struct drm_display_mode *mode,
 				struct drm_display_mode *adjusted_mode)
@ -1515,7 +1508,6 @@ static void mga_encoder_destroy(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs mga_encoder_helper_funcs = {
 	.dpms = mga_encoder_dpms,
-	.mode_fixup = mga_encoder_mode_fixup,
 	.mode_set = mga_encoder_mode_set,
 	.prepare = mga_encoder_prepare,
 	.commit = mga_encoder_commit,
--- a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_dsi_encoder.c
+++ b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_dsi_encoder.c
@ -47,13 +47,6 @@ static const struct drm_encoder_funcs mdp4_dsi_encoder_funcs = {
 	.destroy = mdp4_dsi_encoder_destroy,
 };

-static bool mdp4_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
-					const struct drm_display_mode *mode,
-					struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void mdp4_dsi_encoder_mode_set(struct drm_encoder *encoder,
 				      struct drm_display_mode *mode,
 				      struct drm_display_mode *adjusted_mode)
@ -163,7 +156,6 @@ static void mdp4_dsi_encoder_enable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs mdp4_dsi_encoder_helper_funcs = {
-	.mode_fixup = mdp4_dsi_encoder_mode_fixup,
 	.mode_set = mdp4_dsi_encoder_mode_set,
 	.disable = mdp4_dsi_encoder_disable,
 	.enable = mdp4_dsi_encoder_enable,
--- a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_dtv_encoder.c
+++ b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_dtv_encoder.c
@ -94,13 +94,6 @@ static const struct drm_encoder_funcs mdp4_dtv_encoder_funcs = {
 	.destroy = mdp4_dtv_encoder_destroy,
 };

-static bool mdp4_dtv_encoder_mode_fixup(struct drm_encoder *encoder,
-		const struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void mdp4_dtv_encoder_mode_set(struct drm_encoder *encoder,
 		struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
@ -234,7 +227,6 @@ static void mdp4_dtv_encoder_enable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs mdp4_dtv_encoder_helper_funcs = {
-	.mode_fixup = mdp4_dtv_encoder_mode_fixup,
 	.mode_set = mdp4_dtv_encoder_mode_set,
 	.enable = mdp4_dtv_encoder_enable,
 	.disable = mdp4_dtv_encoder_disable,
--- a/drivers/gpu/drm/msm/mdp/mdp4/mdp4_lcdc_encoder.c
+++ b/drivers/gpu/drm/msm/mdp/mdp4/mdp4_lcdc_encoder.c
@ -260,13 +260,6 @@ static void setup_phy(struct drm_encoder *encoder)
 	mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_CFG0, lvds_phy_cfg0);
 }

-static bool mdp4_lcdc_encoder_mode_fixup(struct drm_encoder *encoder,
-		const struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void mdp4_lcdc_encoder_mode_set(struct drm_encoder *encoder,
 		struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
@ -430,7 +423,6 @@ static void mdp4_lcdc_encoder_enable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs mdp4_lcdc_encoder_helper_funcs = {
-	.mode_fixup = mdp4_lcdc_encoder_mode_fixup,
 	.mode_set = mdp4_lcdc_encoder_mode_set,
 	.disable = mdp4_lcdc_encoder_disable,
 	.enable = mdp4_lcdc_encoder_enable,
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_cmd_encoder.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_cmd_encoder.c
@ -188,13 +188,6 @@ static const struct drm_encoder_funcs mdp5_cmd_encoder_funcs = {
 	.destroy = mdp5_cmd_encoder_destroy,
 };

-static bool mdp5_cmd_encoder_mode_fixup(struct drm_encoder *encoder,
-		const struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void mdp5_cmd_encoder_mode_set(struct drm_encoder *encoder,
 		struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
@ -256,7 +249,6 @@ static void mdp5_cmd_encoder_enable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs mdp5_cmd_encoder_helper_funcs = {
-	.mode_fixup = mdp5_cmd_encoder_mode_fixup,
 	.mode_set = mdp5_cmd_encoder_mode_set,
 	.disable = mdp5_cmd_encoder_disable,
 	.enable = mdp5_cmd_encoder_enable,
@ -340,4 +332,3 @@ fail:

 	return ERR_PTR(ret);
 }
-
--- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
+++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_encoder.c
@ -112,13 +112,6 @@ static const struct drm_encoder_funcs mdp5_encoder_funcs = {
 	.destroy = mdp5_encoder_destroy,
 };

-static bool mdp5_encoder_mode_fixup(struct drm_encoder *encoder,
-		const struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void mdp5_encoder_mode_set(struct drm_encoder *encoder,
 		struct drm_display_mode *mode,
 		struct drm_display_mode *adjusted_mode)
@ -287,7 +280,6 @@ static void mdp5_encoder_enable(struct drm_encoder *encoder)
 }

 static const struct drm_encoder_helper_funcs mdp5_encoder_helper_funcs = {
-	.mode_fixup = mdp5_encoder_mode_fixup,
 	.mode_set = mdp5_encoder_mode_set,
 	.disable = mdp5_encoder_disable,
 	.enable = mdp5_encoder_enable,
--- a/drivers/gpu/drm/msm/msm_fbdev.c
+++ b/drivers/gpu/drm/msm/msm_fbdev.c
@ -62,12 +62,8 @@ static int msm_fbdev_mmap(struct fb_info *info, struct vm_area_struct *vma)
 	struct drm_fb_helper *helper = (struct drm_fb_helper *)info->par;
 	struct msm_fbdev *fbdev = to_msm_fbdev(helper);
 	struct drm_gem_object *drm_obj = fbdev->bo;
-	struct drm_device *dev = helper->dev;
 	int ret = 0;

-	if (drm_device_is_unplugged(dev))
-		return -ENODEV;
-
 	ret = drm_gem_mmap_obj(drm_obj, drm_obj->size, vma);
 	if (ret) {
 		pr_err("%s:drm_gem_mmap_obj fail\n", __func__);
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@ -314,7 +314,7 @@ void nouveau_register_dsm_handler(void)
 	if (!r)
 		return;

-	vga_switcheroo_register_handler(&nouveau_dsm_handler);
+	vga_switcheroo_register_handler(&nouveau_dsm_handler, 0);
 }

 /* Must be called for Optimus models before the card can be turned off */
--- a/drivers/gpu/drm/nouveau/nouveau_connector.c
+++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
@ -27,6 +27,7 @@
 #include <acpi/button.h>

 #include <linux/pm_runtime.h>
+#include <linux/vga_switcheroo.h>

 #include <drm/drmP.h>
 #include <drm/drm_edid.h>
@ -153,6 +154,17 @@ nouveau_connector_ddc_detect(struct drm_connector *connector)
 			if (ret == 0)
 				break;
 		} else
+		if ((vga_switcheroo_handler_flags() &
+		     VGA_SWITCHEROO_CAN_SWITCH_DDC) &&
+		    nv_encoder->dcb->type == DCB_OUTPUT_LVDS &&
+		    nv_encoder->i2c) {
+			int ret;
+			vga_switcheroo_lock_ddc(dev->pdev);
+			ret = nvkm_probe_i2c(nv_encoder->i2c, 0x50);
+			vga_switcheroo_unlock_ddc(dev->pdev);
+			if (ret)
+				break;
+		} else
 		if (nv_encoder->i2c) {
 			if (nvkm_probe_i2c(nv_encoder->i2c, 0x50))
 				break;
@ -265,7 +277,14 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)

 	nv_encoder = nouveau_connector_ddc_detect(connector);
 	if (nv_encoder && (i2c = nv_encoder->i2c) != NULL) {
-		nv_connector->edid = drm_get_edid(connector, i2c);
+		if ((vga_switcheroo_handler_flags() &
+		     VGA_SWITCHEROO_CAN_SWITCH_DDC) &&
+		    nv_connector->type == DCB_CONNECTOR_LVDS)
+			nv_connector->edid = drm_get_edid_switcheroo(connector,
+								     i2c);
+		else
+			nv_connector->edid = drm_get_edid(connector, i2c);
+
 		drm_mode_connector_update_edid_property(connector,
 							nv_connector->edid);
 		if (!nv_connector->edid) {
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@ -22,11 +22,13 @@
 * Authors: Ben Skeggs
 */

+#include <linux/apple-gmux.h>
 #include <linux/console.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/pm_runtime.h>
+#include <linux/vgaarb.h>
 #include <linux/vga_switcheroo.h>

 #include "drmP.h"
@ -312,6 +314,15 @@ static int nouveau_drm_probe(struct pci_dev *pdev,
 	bool boot = false;
 	int ret;

+	/*
+	 * apple-gmux is needed on dual GPU MacBook Pro
+	 * to probe the panel if we're the inactive GPU.
+	 */
+	if (IS_ENABLED(CONFIG_VGA_ARB) && IS_ENABLED(CONFIG_VGA_SWITCHEROO) &&
+	    apple_gmux_present() && pdev != vga_default_device() &&
+	    !vga_switcheroo_handler_flags())
+		return -EPROBE_DEFER;
+
 	/* remove conflicting drivers (vesafb, efifb etc) */
 	aper = alloc_apertures(3);
 	if (!aper)
--- a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
@ -79,7 +79,7 @@ static void omap_gem_dmabuf_release(struct dma_buf *buffer)


 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
-		size_t start, size_t len, enum dma_data_direction dir)
+		enum dma_data_direction dir)
 {
 	struct drm_gem_object *obj = buffer->priv;
 	struct page **pages;
@ -94,7 +94,7 @@ static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
 }

 static void omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
-		size_t start, size_t len, enum dma_data_direction dir)
+		enum dma_data_direction dir)
 {
 	struct drm_gem_object *obj = buffer->priv;
 	omap_gem_put_pages(obj);
--- a/drivers/gpu/drm/qxl/qxl_display.c
+++ b/drivers/gpu/drm/qxl/qxl_display.c
@ -734,14 +734,6 @@ static void qxl_enc_dpms(struct drm_encoder *encoder, int mode)
 	DRM_DEBUG("\n");
 }

-static bool qxl_enc_mode_fixup(struct drm_encoder *encoder,
-			       const struct drm_display_mode *mode,
-			       struct drm_display_mode *adjusted_mode)
-{
-	DRM_DEBUG("\n");
-	return true;
-}
-
 static void qxl_enc_prepare(struct drm_encoder *encoder)
 {
 	DRM_DEBUG("\n");
@ -864,7 +856,6 @@ static struct drm_encoder *qxl_best_encoder(struct drm_connector *connector)

 static const struct drm_encoder_helper_funcs qxl_enc_helper_funcs = {
 	.dpms = qxl_enc_dpms,
-	.mode_fixup = qxl_enc_mode_fixup,
 	.prepare = qxl_enc_prepare,
 	.mode_set = qxl_enc_mode_set,
 	.commit = qxl_enc_commit,
--- a/drivers/gpu/drm/radeon/atombios_encoders.c
+++ b/drivers/gpu/drm/radeon/atombios_encoders.c
@ -2623,16 +2623,8 @@ radeon_atom_ext_dpms(struct drm_encoder *encoder, int mode)

 }

-static bool radeon_atom_ext_mode_fixup(struct drm_encoder *encoder,
-				       const struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static const struct drm_encoder_helper_funcs radeon_atom_ext_helper_funcs = {
 	.dpms = radeon_atom_ext_dpms,
-	.mode_fixup = radeon_atom_ext_mode_fixup,
 	.prepare = radeon_atom_ext_prepare,
 	.mode_set = radeon_atom_ext_mode_set,
 	.commit = radeon_atom_ext_commit,
--- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c
+++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
@ -551,13 +551,14 @@ static bool radeon_atpx_detect(void)
 void radeon_register_atpx_handler(void)
 {
 	bool r;
+	enum vga_switcheroo_handler_flags_t handler_flags = 0;

 	/* detect if we have any ATPX + 2 VGA in the system */
 	r = radeon_atpx_detect();
 	if (!r)
 		return;

-	vga_switcheroo_register_handler(&radeon_atpx_handler);
+	vga_switcheroo_register_handler(&radeon_atpx_handler, handler_flags);
 }

 /**
--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@ -34,6 +34,7 @@
 #include "atom.h"

 #include <linux/pm_runtime.h>
+#include <linux/vga_switcheroo.h>

 static int radeon_dp_handle_hpd(struct drm_connector *connector)
 {
@ -344,6 +345,11 @@ static void radeon_connector_get_edid(struct drm_connector *connector)
 		else if (radeon_connector->ddc_bus)
 			radeon_connector->edid = drm_get_edid(&radeon_connector->base,
 							      &radeon_connector->ddc_bus->adapter);
+	} else if (vga_switcheroo_handler_flags() & VGA_SWITCHEROO_CAN_SWITCH_DDC &&
+		   connector->connector_type == DRM_MODE_CONNECTOR_LVDS &&
+		   radeon_connector->ddc_bus) {
+		radeon_connector->edid = drm_get_edid_switcheroo(&radeon_connector->base,
+								 &radeon_connector->ddc_bus->adapter);
 	} else if (radeon_connector->ddc_bus) {
 		radeon_connector->edid = drm_get_edid(&radeon_connector->base,
 						      &radeon_connector->ddc_bus->adapter);
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@ -34,9 +34,11 @@
 #include "radeon_drv.h"

 #include <drm/drm_pciids.h>
+#include <linux/apple-gmux.h>
 #include <linux/console.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/vgaarb.h>
 #include <linux/vga_switcheroo.h>
 #include <drm/drm_gem.h>

@ -319,6 +321,15 @@ static int radeon_pci_probe(struct pci_dev *pdev,
 {
 	int ret;

+	/*
+	 * apple-gmux is needed on dual GPU MacBook Pro
+	 * to probe the panel if we're the inactive GPU.
+	 */
+	if (IS_ENABLED(CONFIG_VGA_ARB) && IS_ENABLED(CONFIG_VGA_SWITCHEROO) &&
+	    apple_gmux_present() && pdev != vga_default_device() &&
+	    !vga_switcheroo_handler_flags())
+		return -EPROBE_DEFER;
+
 	/* Get rid of things like offb */
 	ret = radeon_kick_out_firmware_fb(pdev);
 	if (ret)
--- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c
@ -875,13 +875,6 @@ static void dw_mipi_dsi_encoder_disable(struct drm_encoder *encoder)
 	clk_disable_unprepare(dsi->pclk);
 }

-static bool dw_mipi_dsi_encoder_mode_fixup(struct drm_encoder *encoder,
-					const struct drm_display_mode *mode,
-					struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void dw_mipi_dsi_encoder_commit(struct drm_encoder *encoder)
 {
 	struct dw_mipi_dsi *dsi = encoder_to_dsi(encoder);
@ -931,7 +924,6 @@ static void dw_mipi_dsi_encoder_commit(struct drm_encoder *encoder)

 static struct drm_encoder_helper_funcs
 dw_mipi_dsi_encoder_helper_funcs = {
-	.mode_fixup = dw_mipi_dsi_encoder_mode_fixup,
 	.commit = dw_mipi_dsi_encoder_commit,
 	.mode_set = dw_mipi_dsi_encoder_mode_set,
 	.disable = dw_mipi_dsi_encoder_disable,
--- a/drivers/gpu/drm/sti/sti_tvout.c
+++ b/drivers/gpu/drm/sti/sti_tvout.c
@ -440,13 +440,6 @@ static void sti_tvout_encoder_dpms(struct drm_encoder *encoder, int mode)
 {
 }

-static bool sti_tvout_encoder_mode_fixup(struct drm_encoder *encoder,
-				       const struct drm_display_mode *mode,
-				       struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void sti_tvout_encoder_mode_set(struct drm_encoder *encoder,
 				       struct drm_display_mode *mode,
 				       struct drm_display_mode *adjusted_mode)
@ -486,7 +479,6 @@ static void sti_dvo_encoder_disable(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs sti_dvo_encoder_helper_funcs = {
 	.dpms = sti_tvout_encoder_dpms,
-	.mode_fixup = sti_tvout_encoder_mode_fixup,
 	.mode_set = sti_tvout_encoder_mode_set,
 	.prepare = sti_tvout_encoder_prepare,
 	.commit = sti_dvo_encoder_commit,
@ -540,7 +532,6 @@ static void sti_hda_encoder_disable(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs sti_hda_encoder_helper_funcs = {
 	.dpms = sti_tvout_encoder_dpms,
-	.mode_fixup = sti_tvout_encoder_mode_fixup,
 	.mode_set = sti_tvout_encoder_mode_set,
 	.prepare = sti_tvout_encoder_prepare,
 	.commit = sti_hda_encoder_commit,
@ -589,7 +580,6 @@ static void sti_hdmi_encoder_disable(struct drm_encoder *encoder)

 static const struct drm_encoder_helper_funcs sti_hdmi_encoder_helper_funcs = {
 	.dpms = sti_tvout_encoder_dpms,
-	.mode_fixup = sti_tvout_encoder_mode_fixup,
 	.mode_set = sti_tvout_encoder_mode_set,
 	.prepare = sti_tvout_encoder_prepare,
 	.commit = sti_hdmi_encoder_commit,
--- a/drivers/gpu/drm/tilcdc/tilcdc_panel.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
@ -70,14 +70,6 @@ static void panel_encoder_dpms(struct drm_encoder *encoder, int mode)
 					 mode == DRM_MODE_DPMS_ON ? 1 : 0);
 }

-static bool panel_encoder_mode_fixup(struct drm_encoder *encoder,
-		const struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
-{
-	/* nothing needed */
-	return true;
-}
-
 static void panel_encoder_prepare(struct drm_encoder *encoder)
 {
 	struct panel_encoder *panel_encoder = to_panel_encoder(encoder);
@ -103,7 +95,6 @@ static const struct drm_encoder_funcs panel_encoder_funcs = {

 static const struct drm_encoder_helper_funcs panel_encoder_helper_funcs = {
 		.dpms           = panel_encoder_dpms,
-		.mode_fixup     = panel_encoder_mode_fixup,
 		.prepare        = panel_encoder_prepare,
 		.commit         = panel_encoder_commit,
 		.mode_set       = panel_encoder_mode_set,
--- a/drivers/gpu/drm/tilcdc/tilcdc_tfp410.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_tfp410.c
@ -80,14 +80,6 @@ static void tfp410_encoder_dpms(struct drm_encoder *encoder, int mode)
 	tfp410_encoder->dpms = mode;
 }

-static bool tfp410_encoder_mode_fixup(struct drm_encoder *encoder,
-		const struct drm_display_mode *mode,
-		struct drm_display_mode *adjusted_mode)
-{
-	/* nothing needed */
-	return true;
-}
-
 static void tfp410_encoder_prepare(struct drm_encoder *encoder)
 {
 	tfp410_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
@ -112,7 +104,6 @@ static const struct drm_encoder_funcs tfp410_encoder_funcs = {

 static const struct drm_encoder_helper_funcs tfp410_encoder_helper_funcs = {
 		.dpms           = tfp410_encoder_dpms,
-		.mode_fixup     = tfp410_encoder_mode_fixup,
 		.prepare        = tfp410_encoder_prepare,
 		.commit         = tfp410_encoder_commit,
 		.mode_set       = tfp410_encoder_mode_set,
--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@ -125,17 +125,5 @@ static struct usb_driver udl_driver = {
 	.disconnect = udl_usb_disconnect,
 	.id_table = id_table,
 };
-
-static int __init udl_init(void)
-{
-	return usb_register(&udl_driver);
-}
-
-static void __exit udl_exit(void)
-{
-	usb_deregister(&udl_driver);
-}
-
-module_init(udl_init);
-module_exit(udl_exit);
+module_usb_driver(udl_driver);
 MODULE_LICENSE("GPL");
--- a/drivers/gpu/drm/udl/udl_encoder.c
+++ b/drivers/gpu/drm/udl/udl_encoder.c
@ -26,13 +26,6 @@ static void udl_encoder_disable(struct drm_encoder *encoder)
 {
 }

-static bool udl_mode_fixup(struct drm_encoder *encoder,
-			   const struct drm_display_mode *mode,
-			   struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void udl_encoder_prepare(struct drm_encoder *encoder)
 {
 }
@ -54,7 +47,6 @@ udl_encoder_dpms(struct drm_encoder *encoder, int mode)

 static const struct drm_encoder_helper_funcs udl_helper_funcs = {
 	.dpms = udl_encoder_dpms,
-	.mode_fixup = udl_mode_fixup,
 	.prepare = udl_encoder_prepare,
 	.mode_set = udl_encoder_mode_set,
 	.commit = udl_encoder_commit,
--- a/drivers/gpu/drm/udl/udl_fb.c
+++ b/drivers/gpu/drm/udl/udl_fb.c
@ -409,7 +409,6 @@ static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,

 	if (ufb->obj->base.import_attach) {
 		ret = dma_buf_begin_cpu_access(ufb->obj->base.import_attach->dmabuf,
-					       0, ufb->obj->base.size,
 					       DMA_FROM_DEVICE);
 		if (ret)
 			goto unlock;
@ -425,7 +424,6 @@ static int udl_user_framebuffer_dirty(struct drm_framebuffer *fb,

 	if (ufb->obj->base.import_attach) {
 		dma_buf_end_cpu_access(ufb->obj->base.import_attach->dmabuf,
-				       0, ufb->obj->base.size,
 				       DMA_FROM_DEVICE);
 	}

--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@ -282,13 +282,6 @@ static const struct drm_crtc_helper_funcs virtio_gpu_crtc_helper_funcs = {
 	.atomic_check  = virtio_gpu_crtc_atomic_check,
 };

-static bool virtio_gpu_enc_mode_fixup(struct drm_encoder *encoder,
-				      const struct drm_display_mode *mode,
-				      struct drm_display_mode *adjusted_mode)
-{
-	return true;
-}
-
 static void virtio_gpu_enc_mode_set(struct drm_encoder *encoder,
 				    struct drm_display_mode *mode,
 				    struct drm_display_mode *adjusted_mode)
@ -362,7 +355,6 @@ virtio_gpu_best_encoder(struct drm_connector *connector)
 }

 static const struct drm_encoder_helper_funcs virtio_gpu_enc_helper_funcs = {
-	.mode_fixup = virtio_gpu_enc_mode_fixup,
 	.mode_set   = virtio_gpu_enc_mode_set,
 	.enable     = virtio_gpu_enc_enable,
 	.disable    = virtio_gpu_enc_disable,
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@ -74,9 +74,17 @@
 * there can thus be up to three clients: Two vga clients (GPUs) and one audio
 * client (on the discrete GPU). The code is mostly prepared to support
 * machines with more than two GPUs should they become available.
+ *
 * The GPU to which the outputs are currently switched is called the
 * active client in vga_switcheroo parlance. The GPU not in use is the
- * inactive client.
+ * inactive client. When the inactive client's DRM driver is loaded,
+ * it will be unable to probe the panel's EDID and hence depends on
+ * VBIOS to provide its display modes. If the VBIOS modes are bogus or
+ * if there is no VBIOS at all (which is common on the MacBook Pro),
+ * a client may alternatively request that the DDC lines are temporarily
+ * switched to it, provided that the handler supports this. Switching
+ * only the DDC lines and not the entire output avoids unnecessary
+ * flickering.
 */

 /**
@ -126,6 +134,10 @@ static DEFINE_MUTEX(vgasr_mutex);
 * 	(counting only vga clients, not audio clients)
 * @clients: list of registered clients
 * @handler: registered handler
+ * @handler_flags: flags of registered handler
+ * @mux_hw_lock: protects mux state
+ *	(in particular while DDC lines are temporarily switched)
+ * @old_ddc_owner: client to which DDC lines will be switched back on unlock
 *
 * vga_switcheroo private data. Currently only one vga_switcheroo instance
 * per system is supported.
@ -142,6 +154,9 @@ struct vgasr_priv {
 	struct list_head clients;

 	const struct vga_switcheroo_handler *handler;
+	enum vga_switcheroo_handler_flags_t handler_flags;
+	struct mutex mux_hw_lock;
+	int old_ddc_owner;
 };

 #define ID_BIT_AUDIO		0x100
@ -156,6 +171,7 @@ static void vga_switcheroo_debugfs_fini(struct vgasr_priv *priv);
 /* only one switcheroo per system */
 static struct vgasr_priv vgasr_priv = {
 	.clients = LIST_HEAD_INIT(vgasr_priv.clients),
+	.mux_hw_lock = __MUTEX_INITIALIZER(vgasr_priv.mux_hw_lock),
 };

 static bool vga_switcheroo_ready(void)
@ -190,13 +206,15 @@ static void vga_switcheroo_enable(void)
 /**
 * vga_switcheroo_register_handler() - register handler
 * @handler: handler callbacks
+ * @handler_flags: handler flags
 *
 * Register handler. Enable vga_switcheroo if two vga clients have already
 * registered.
 *
 * Return: 0 on success, -EINVAL if a handler was already registered.
 */
-int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler)
+int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
+				    enum vga_switcheroo_handler_flags_t handler_flags)
 {
 	mutex_lock(&vgasr_mutex);
 	if (vgasr_priv.handler) {
@ -205,6 +223,7 @@ int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler
 	}

 	vgasr_priv.handler = handler;
+	vgasr_priv.handler_flags = handler_flags;
 	if (vga_switcheroo_ready()) {
 		pr_info("enabled\n");
 		vga_switcheroo_enable();
@ -222,16 +241,33 @@ EXPORT_SYMBOL(vga_switcheroo_register_handler);
 void vga_switcheroo_unregister_handler(void)
 {
 	mutex_lock(&vgasr_mutex);
+	mutex_lock(&vgasr_priv.mux_hw_lock);
+	vgasr_priv.handler_flags = 0;
 	vgasr_priv.handler = NULL;
 	if (vgasr_priv.active) {
 		pr_info("disabled\n");
 		vga_switcheroo_debugfs_fini(&vgasr_priv);
 		vgasr_priv.active = false;
 	}
+	mutex_unlock(&vgasr_priv.mux_hw_lock);
 	mutex_unlock(&vgasr_mutex);
 }
 EXPORT_SYMBOL(vga_switcheroo_unregister_handler);

+/**
+ * vga_switcheroo_handler_flags() - obtain handler flags
+ *
+ * Helper for clients to obtain the handler flags bitmask.
+ *
+ * Return: Handler flags. A value of 0 means that no handler is registered
+ * or that the handler has no special capabilities.
+ */
+enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void)
+{
+	return vgasr_priv.handler_flags;
+}
+EXPORT_SYMBOL(vga_switcheroo_handler_flags);
+
 static int register_client(struct pci_dev *pdev,
 			   const struct vga_switcheroo_client_ops *ops,
 			   enum vga_switcheroo_client_id id, bool active,
@ -412,6 +448,76 @@ void vga_switcheroo_client_fb_set(struct pci_dev *pdev,
 }
 EXPORT_SYMBOL(vga_switcheroo_client_fb_set);

+/**
+ * vga_switcheroo_lock_ddc() - temporarily switch DDC lines to a given client
+ * @pdev: client pci device
+ *
+ * Temporarily switch DDC lines to the client identified by @pdev
+ * (but leave the outputs otherwise switched to where they are).
+ * This allows the inactive client to probe EDID. The DDC lines must
+ * afterwards be switched back by calling vga_switcheroo_unlock_ddc(),
+ * even if this function returns an error.
+ *
+ * Return: Previous DDC owner on success or a negative int on error.
+ * Specifically, %-ENODEV if no handler has registered or if the handler
+ * does not support switching the DDC lines. Also, a negative value
+ * returned by the handler is propagated back to the caller.
+ * The return value has merely an informational purpose for any caller
+ * which might be interested in it. It is acceptable to ignore the return
+ * value and simply rely on the result of the subsequent EDID probe,
+ * which will be %NULL if DDC switching failed.
+ */
+int vga_switcheroo_lock_ddc(struct pci_dev *pdev)
+{
+	enum vga_switcheroo_client_id id;
+
+	mutex_lock(&vgasr_priv.mux_hw_lock);
+	if (!vgasr_priv.handler || !vgasr_priv.handler->switch_ddc) {
+		vgasr_priv.old_ddc_owner = -ENODEV;
+		return -ENODEV;
+	}
+
+	id = vgasr_priv.handler->get_client_id(pdev);
+	vgasr_priv.old_ddc_owner = vgasr_priv.handler->switch_ddc(id);
+	return vgasr_priv.old_ddc_owner;
+}
+EXPORT_SYMBOL(vga_switcheroo_lock_ddc);
+
+/**
+ * vga_switcheroo_unlock_ddc() - switch DDC lines back to previous owner
+ * @pdev: client pci device
+ *
+ * Switch DDC lines back to the previous owner after calling
+ * vga_switcheroo_lock_ddc(). This must be called even if
+ * vga_switcheroo_lock_ddc() returned an error.
+ *
+ * Return: Previous DDC owner on success (i.e. the client identifier of @pdev)
+ * or a negative int on error.
+ * Specifically, %-ENODEV if no handler has registered or if the handler
+ * does not support switching the DDC lines. Also, a negative value
+ * returned by the handler is propagated back to the caller.
+ * Finally, invoking this function without calling vga_switcheroo_lock_ddc()
+ * first is not allowed and will result in %-EINVAL.
+ */
+int vga_switcheroo_unlock_ddc(struct pci_dev *pdev)
+{
+	enum vga_switcheroo_client_id id;
+	int ret = vgasr_priv.old_ddc_owner;
+
+	if (WARN_ON_ONCE(!mutex_is_locked(&vgasr_priv.mux_hw_lock)))
+		return -EINVAL;
+
+	if (vgasr_priv.old_ddc_owner >= 0) {
+		id = vgasr_priv.handler->get_client_id(pdev);
+		if (vgasr_priv.old_ddc_owner != id)
+			ret = vgasr_priv.handler->switch_ddc(
+						     vgasr_priv.old_ddc_owner);
+	}
+	mutex_unlock(&vgasr_priv.mux_hw_lock);
+	return ret;
+}
+EXPORT_SYMBOL(vga_switcheroo_unlock_ddc);
+
 /**
 * DOC: Manual switching and manual power control
 *
@ -549,7 +655,9 @@ static int vga_switchto_stage2(struct vga_switcheroo_client *new_client)
 		console_unlock();
 	}

+	mutex_lock(&vgasr_priv.mux_hw_lock);
 	ret = vgasr_priv.handler->switchto(new_client->id);
+	mutex_unlock(&vgasr_priv.mux_hw_lock);
 	if (ret)
 		return ret;

@ -664,7 +772,9 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
 	vgasr_priv.delayed_switch_active = false;

 	if (just_mux) {
+		mutex_lock(&vgasr_priv.mux_hw_lock);
 		ret = vgasr_priv.handler->switchto(client_id);
+		mutex_unlock(&vgasr_priv.mux_hw_lock);
 		goto out;
 	}

@ -876,8 +986,11 @@ static int vga_switcheroo_runtime_suspend(struct device *dev)
 	if (ret)
 		return ret;
 	mutex_lock(&vgasr_mutex);
-	if (vgasr_priv.handler->switchto)
+	if (vgasr_priv.handler->switchto) {
+		mutex_lock(&vgasr_priv.mux_hw_lock);
 		vgasr_priv.handler->switchto(VGA_SWITCHEROO_IGD);
+		mutex_unlock(&vgasr_priv.mux_hw_lock);
+	}
 	vga_switcheroo_power_switch(pdev, VGA_SWITCHEROO_OFF);
 	mutex_unlock(&vgasr_mutex);
 	return 0;
--- a/drivers/platform/x86/apple-gmux.c
+++ b/drivers/platform/x86/apple-gmux.c
@ -19,6 +19,7 @@
 #include <linux/acpi.h>
 #include <linux/pnp.h>
 #include <linux/apple_bl.h>
+#include <linux/apple-gmux.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/pci.h>
@ -57,7 +58,9 @@ struct apple_gmux_data {
 	/* switcheroo data */
 	acpi_handle dhandle;
 	int gpe;
-	enum vga_switcheroo_client_id resume_client_id;
+	enum vga_switcheroo_client_id switch_state_display;
+	enum vga_switcheroo_client_id switch_state_ddc;
+	enum vga_switcheroo_client_id switch_state_external;
 	enum vga_switcheroo_state power_state;
 	struct completion powerchange_done;
 };
@ -368,21 +371,72 @@ static const struct backlight_ops gmux_bl_ops = {
 * for the selected GPU.
 */

+static void gmux_read_switch_state(struct apple_gmux_data *gmux_data)
+{
+	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DDC) == 1)
+		gmux_data->switch_state_ddc = VGA_SWITCHEROO_IGD;
+	else
+		gmux_data->switch_state_ddc = VGA_SWITCHEROO_DIS;
+
+	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
+		gmux_data->switch_state_display = VGA_SWITCHEROO_IGD;
+	else
+		gmux_data->switch_state_display = VGA_SWITCHEROO_DIS;
+
+	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL) == 2)
+		gmux_data->switch_state_external = VGA_SWITCHEROO_IGD;
+	else
+		gmux_data->switch_state_external = VGA_SWITCHEROO_DIS;
+}
+
+static void gmux_write_switch_state(struct apple_gmux_data *gmux_data)
+{
+	if (gmux_data->switch_state_ddc == VGA_SWITCHEROO_IGD)
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 1);
+	else
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DDC, 2);
+
+	if (gmux_data->switch_state_display == VGA_SWITCHEROO_IGD)
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
+	else
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
+
+	if (gmux_data->switch_state_external == VGA_SWITCHEROO_IGD)
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
+	else
+		gmux_write8(gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
+}
+
 static int gmux_switchto(enum vga_switcheroo_client_id id)
 {
-	if (id == VGA_SWITCHEROO_IGD) {
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 2);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 2);
-	} else {
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DISPLAY, 3);
-		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_EXTERNAL, 3);
-	}
+	apple_gmux_data->switch_state_ddc = id;
+	apple_gmux_data->switch_state_display = id;
+	apple_gmux_data->switch_state_external = id;
+
+	gmux_write_switch_state(apple_gmux_data);

 	return 0;
 }

+static int gmux_switch_ddc(enum vga_switcheroo_client_id id)
+{
+	enum vga_switcheroo_client_id old_ddc_owner =
+		apple_gmux_data->switch_state_ddc;
+
+	if (id == old_ddc_owner)
+		return id;
+
+	pr_debug("Switching DDC from %d to %d\n", old_ddc_owner, id);
+	apple_gmux_data->switch_state_ddc = id;
+
+	if (id == VGA_SWITCHEROO_IGD)
+		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 1);
+	else
+		gmux_write8(apple_gmux_data, GMUX_PORT_SWITCH_DDC, 2);
+
+	return old_ddc_owner;
+}
+
 /**
 * DOC: Power control
 *
@ -440,21 +494,19 @@ static int gmux_get_client_id(struct pci_dev *pdev)
 		return VGA_SWITCHEROO_DIS;
 }

-static enum vga_switcheroo_client_id
-gmux_active_client(struct apple_gmux_data *gmux_data)
-{
-	if (gmux_read8(gmux_data, GMUX_PORT_SWITCH_DISPLAY) == 2)
-		return VGA_SWITCHEROO_IGD;
-
-	return VGA_SWITCHEROO_DIS;
-}
-
-static const struct vga_switcheroo_handler gmux_handler = {
+static const struct vga_switcheroo_handler gmux_handler_indexed = {
 	.switchto = gmux_switchto,
 	.power_state = gmux_set_power_state,
 	.get_client_id = gmux_get_client_id,
 };

+static const struct vga_switcheroo_handler gmux_handler_classic = {
+	.switchto = gmux_switchto,
+	.switch_ddc = gmux_switch_ddc,
+	.power_state = gmux_set_power_state,
+	.get_client_id = gmux_get_client_id,
+};
+
 /**
 * DOC: Interrupt
 *
@ -513,7 +565,6 @@ static int gmux_suspend(struct device *dev)
 	struct pnp_dev *pnp = to_pnp_dev(dev);
 	struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);

-	gmux_data->resume_client_id = gmux_active_client(gmux_data);
 	gmux_disable_interrupts(gmux_data);
 	return 0;
 }
@ -524,7 +575,7 @@ static int gmux_resume(struct device *dev)
 	struct apple_gmux_data *gmux_data = pnp_get_drvdata(pnp);

 	gmux_enable_interrupts(gmux_data);
-	gmux_switchto(gmux_data->resume_client_id);
+	gmux_write_switch_state(gmux_data);
 	if (gmux_data->power_state == VGA_SWITCHEROO_OFF)
 		gmux_set_discrete_state(gmux_data, gmux_data->power_state);
 	return 0;
@ -704,9 +755,23 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id)
 	apple_gmux_data = gmux_data;
 	init_completion(&gmux_data->powerchange_done);
 	gmux_enable_interrupts(gmux_data);
+	gmux_read_switch_state(gmux_data);

-	if (vga_switcheroo_register_handler(&gmux_handler)) {
-		ret = -ENODEV;
+	/*
+	 * Retina MacBook Pros cannot switch the panel's AUX separately
+	 * and need eDP pre-calibration. They are distinguishable from
+	 * pre-retinas by having an "indexed" gmux.
+	 *
+	 * Pre-retina MacBook Pros can switch the panel's DDC separately.
+	 */
+	if (gmux_data->indexed)
+		ret = vga_switcheroo_register_handler(&gmux_handler_indexed,
+					      VGA_SWITCHEROO_NEEDS_EDP_CONFIG);
+	else
+		ret = vga_switcheroo_register_handler(&gmux_handler_classic,
+					      VGA_SWITCHEROO_CAN_SWITCH_DDC);
+	if (ret) {
+		pr_err("Failed to register vga_switcheroo handler\n");
 		goto err_register_handler;
 	}

@ -764,7 +829,7 @@ static void gmux_remove(struct pnp_dev *pnp)
 }

 static const struct pnp_device_id gmux_device_ids[] = {
-	{"APP000B", 0},
+	{GMUX_ACPI_HID, 0},
 	{"", 0}
 };

--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@ -1057,8 +1057,7 @@ static void ion_dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long offset,
 {
 }

-static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start,
-					size_t len,
+static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
 					enum dma_data_direction direction)
 {
 	struct ion_buffer *buffer = dmabuf->priv;
@ -1076,8 +1075,7 @@ static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, size_t start,
 	return PTR_ERR_OR_ZERO(vaddr);
 }

-static void ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf, size_t start,
-				       size_t len,
+static void ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
 				       enum dma_data_direction direction)
 {
 	struct ion_buffer *buffer = dmabuf->priv;
--- a/drivers/staging/android/ion/ion_test.c
+++ b/drivers/staging/android/ion/ion_test.c
@ -109,7 +109,7 @@ static int ion_handle_test_kernel(struct dma_buf *dma_buf, void __user *ptr,
 	if (offset > dma_buf->size || size > dma_buf->size - offset)
 		return -EINVAL;

-	ret = dma_buf_begin_cpu_access(dma_buf, offset, size, dir);
+	ret = dma_buf_begin_cpu_access(dma_buf, dir);
 	if (ret)
 		return ret;

@ -139,7 +139,7 @@ static int ion_handle_test_kernel(struct dma_buf *dma_buf, void __user *ptr,
 		copy_offset = 0;
 	}
 err:
-	dma_buf_end_cpu_access(dma_buf, offset, size, dir);
+	dma_buf_end_cpu_access(dma_buf, dir);
 	return ret;
 }

--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@ -307,6 +307,7 @@ struct drm_plane_helper_funcs;
 * @connectors_changed: connectors to this crtc have been updated
 * @plane_mask: bitmask of (1 << drm_plane_index(plane)) of attached planes
 * @connector_mask: bitmask of (1 << drm_connector_index(connector)) of attached connectors
+ * @encoder_mask: bitmask of (1 << drm_encoder_index(encoder)) of attached encoders
 * @last_vblank_count: for helpers and drivers to capture the vblank of the
 * 	update to ensure framebuffer cleanup isn't done too early
 * @adjusted_mode: for use by helpers and drivers to compute adjusted mode timings
@ -341,6 +342,7 @@ struct drm_crtc_state {
 	u32 plane_mask;

 	u32 connector_mask;
+	u32 encoder_mask;

 	/* last_vblank_count: for vblank waits before cleanup */
 	u32 last_vblank_count;
@ -2153,6 +2155,17 @@ struct drm_mode_config {
 	list_for_each_entry((plane), &(dev)->mode_config.plane_list, head) \
 		for_each_if ((plane_mask) & (1 << drm_plane_index(plane)))

+/**
+ * drm_for_each_encoder_mask - iterate over encoders specified by bitmask
+ * @encoder: the loop cursor
+ * @dev: the DRM device
+ * @encoder_mask: bitmask of encoder indices
+ *
+ * Iterate over all encoders specified by bitmask.
+ */
+#define drm_for_each_encoder_mask(encoder, dev, encoder_mask) \
+	list_for_each_entry((encoder), &(dev)->mode_config.encoder_list, head) \
+		for_each_if ((encoder_mask) & (1 << drm_encoder_index(encoder)))

 #define obj_to_crtc(x) container_of(x, struct drm_crtc, base)
 #define obj_to_connector(x) container_of(x, struct drm_connector, base)
@ -2225,6 +2238,7 @@ int drm_encoder_init(struct drm_device *dev,
 		     struct drm_encoder *encoder,
 		     const struct drm_encoder_funcs *funcs,
 		     int encoder_type, const char *name, ...);
+extern unsigned int drm_encoder_index(struct drm_encoder *encoder);

 /**
 * drm_encoder_crtc_ok - can a given crtc drive a given encoder?
@ -2282,6 +2296,8 @@ extern void drm_property_destroy_user_blobs(struct drm_device *dev,
 extern bool drm_probe_ddc(struct i2c_adapter *adapter);
 extern struct edid *drm_get_edid(struct drm_connector *connector,
 				 struct i2c_adapter *adapter);
+extern struct edid *drm_get_edid_switcheroo(struct drm_connector *connector,
+					    struct i2c_adapter *adapter);
 extern struct edid *drm_edid_duplicate(const struct edid *edid);
 extern int drm_add_edid_modes(struct drm_connector *connector, struct edid *edid);
 extern void drm_mode_config_init(struct drm_device *dev);
@ -2482,6 +2498,8 @@ extern int drm_format_num_planes(uint32_t format);
 extern int drm_format_plane_cpp(uint32_t format, int plane);
 extern int drm_format_horz_chroma_subsampling(uint32_t format);
 extern int drm_format_vert_chroma_subsampling(uint32_t format);
+extern int drm_format_plane_width(int width, uint32_t format, int plane);
+extern int drm_format_plane_height(int height, uint32_t format, int plane);
 extern const char *drm_get_format_name(uint32_t format);
 extern struct drm_property *drm_mode_create_rotation_property(struct drm_device *dev,
 							      unsigned int supported_rotations);
--- a/include/drm/drm_dp_aux_dev.h
+++ b/include/drm/drm_dp_aux_dev.h
@ -0,0 +1,62 @@
+/*
+ * Copyright © 2015 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ *    Rafael Antognolli <rafael.antognolli@intel.com>
+ *
+ */
+
+#ifndef DRM_DP_AUX_DEV
+#define DRM_DP_AUX_DEV
+
+#include <drm/drm_dp_helper.h>
+
+#ifdef CONFIG_DRM_DP_AUX_CHARDEV
+
+int drm_dp_aux_dev_init(void);
+void drm_dp_aux_dev_exit(void);
+int drm_dp_aux_register_devnode(struct drm_dp_aux *aux);
+void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux);
+
+#else
+
+static inline int drm_dp_aux_dev_init(void)
+{
+	return 0;
+}
+
+static inline void drm_dp_aux_dev_exit(void)
+{
+}
+
+static inline int drm_dp_aux_register_devnode(struct drm_dp_aux *aux)
+{
+	return 0;
+}
+
+static inline void drm_dp_aux_unregister_devnode(struct drm_dp_aux *aux)
+{
+}
+
+#endif
+
+#endif
--- a/include/drm/drm_fb_helper.h
+++ b/include/drm/drm_fb_helper.h
@ -219,6 +219,7 @@ struct drm_fb_helper {
 };

 #ifdef CONFIG_DRM_FBDEV_EMULATION
+int drm_fb_helper_modinit(void);
 void drm_fb_helper_prepare(struct drm_device *dev, struct drm_fb_helper *helper,
 			   const struct drm_fb_helper_funcs *funcs);
 int drm_fb_helper_init(struct drm_device *dev,
@ -283,6 +284,11 @@ int drm_fb_helper_add_one_connector(struct drm_fb_helper *fb_helper, struct drm_
 int drm_fb_helper_remove_one_connector(struct drm_fb_helper *fb_helper,
 				       struct drm_connector *connector);
 #else
+static inline int drm_fb_helper_modinit(void)
+{
+	return 0;
+}
+
 static inline void drm_fb_helper_prepare(struct drm_device *dev,
 					struct drm_fb_helper *helper,
 					const struct drm_fb_helper_funcs *funcs)
--- a/include/drm/drm_modeset_helper_vtables.h
+++ b/include/drm/drm_modeset_helper_vtables.h
@ -439,7 +439,7 @@ struct drm_encoder_helper_funcs {
 	 * can be modified by this callback and does not need to match mode.
 	 *
 	 * This function is used by both legacy CRTC helpers and atomic helpers.
-	 * With atomic helpers it is optional.
+	 * This hook is optional.
 	 *
 	 * NOTE:
 	 *
--- a/include/linux/apple-gmux.h
+++ b/include/linux/apple-gmux.h
@ -0,0 +1,50 @@
+/*
+ * apple-gmux.h - microcontroller built into dual GPU MacBook Pro & Mac Pro
+ * Copyright (C) 2015 Lukas Wunner <lukas@wunner.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2) as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LINUX_APPLE_GMUX_H
+#define LINUX_APPLE_GMUX_H
+
+#include <linux/acpi.h>
+
+#define GMUX_ACPI_HID "APP000B"
+
+#if IS_ENABLED(CONFIG_APPLE_GMUX)
+
+/**
+ * apple_gmux_present() - detect if gmux is built into the machine
+ *
+ * Drivers may use this to activate quirks specific to dual GPU MacBook Pros
+ * and Mac Pros, e.g. for deferred probing, runtime pm and backlight.
+ *
+ * Return: %true if gmux is present and the kernel was configured
+ * with CONFIG_APPLE_GMUX, %false otherwise.
+ */
+static inline bool apple_gmux_present(void)
+{
+	return acpi_dev_present(GMUX_ACPI_HID);
+}
+
+#else  /* !CONFIG_APPLE_GMUX */
+
+static inline bool apple_gmux_present(void)
+{
+	return false;
+}
+
+#endif /* !CONFIG_APPLE_GMUX */
+
+#endif /* LINUX_APPLE_GMUX_H */
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@ -54,7 +54,7 @@ struct dma_buf_attachment;
 * @release: release this buffer; to be called after the last dma_buf_put.
 * @begin_cpu_access: [optional] called before cpu access to invalidate cpu
 * 		      caches and allocate backing storage (if not yet done)
- * 		      respectively pin the objet into memory.
+ * 		      respectively pin the object into memory.
 * @end_cpu_access: [optional] called after cpu access to flush caches.
 * @kmap_atomic: maps a page from the buffer into kernel address
 * 		 space, users may not block until the subsequent unmap call.
@ -93,10 +93,8 @@ struct dma_buf_ops {
 	/* after final dma_buf_put() */
 	void (*release)(struct dma_buf *);

-	int (*begin_cpu_access)(struct dma_buf *, size_t, size_t,
-				enum dma_data_direction);
-	void (*end_cpu_access)(struct dma_buf *, size_t, size_t,
-			       enum dma_data_direction);
+	int (*begin_cpu_access)(struct dma_buf *, enum dma_data_direction);
+	void (*end_cpu_access)(struct dma_buf *, enum dma_data_direction);
 	void *(*kmap_atomic)(struct dma_buf *, unsigned long);
 	void (*kunmap_atomic)(struct dma_buf *, unsigned long, void *);
 	void *(*kmap)(struct dma_buf *, unsigned long);
@ -224,9 +222,9 @@ struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *,
 					enum dma_data_direction);
 void dma_buf_unmap_attachment(struct dma_buf_attachment *, struct sg_table *,
 				enum dma_data_direction);
-int dma_buf_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t len,
+int dma_buf_begin_cpu_access(struct dma_buf *dma_buf,
 			     enum dma_data_direction dir);
-void dma_buf_end_cpu_access(struct dma_buf *dma_buf, size_t start, size_t len,
+void dma_buf_end_cpu_access(struct dma_buf *dma_buf,
 			    enum dma_data_direction dir);
 void *dma_buf_kmap_atomic(struct dma_buf *, unsigned long);
 void dma_buf_kunmap_atomic(struct dma_buf *, unsigned long, void *);
--- a/include/linux/vga_switcheroo.h
+++ b/include/linux/vga_switcheroo.h
@ -35,6 +35,26 @@

 struct pci_dev;

+/**
+ * enum vga_switcheroo_handler_flags_t - handler flags bitmask
+ * @VGA_SWITCHEROO_CAN_SWITCH_DDC: whether the handler is able to switch the
+ * 	DDC lines separately. This signals to clients that they should call
+ * 	drm_get_edid_switcheroo() to probe the EDID
+ * @VGA_SWITCHEROO_NEEDS_EDP_CONFIG: whether the handler is unable to switch
+ * 	the AUX channel separately. This signals to clients that the active
+ * 	GPU needs to train the link and communicate the link parameters to the
+ * 	inactive GPU (mediated by vga_switcheroo). The inactive GPU may then
+ * 	skip the AUX handshake and set up its output with these pre-calibrated
+ * 	values (DisplayPort specification v1.1a, section 2.5.3.3)
+ *
+ * Handler flags bitmask. Used by handlers to declare their capabilities upon
+ * registering with vga_switcheroo.
+ */
+enum vga_switcheroo_handler_flags_t {
+	VGA_SWITCHEROO_CAN_SWITCH_DDC	= (1 << 0),
+	VGA_SWITCHEROO_NEEDS_EDP_CONFIG	= (1 << 1),
+};
+
 /**
 * enum vga_switcheroo_state - client power state
 * @VGA_SWITCHEROO_OFF: off
@ -82,6 +102,9 @@ enum vga_switcheroo_client_id {
 * 	Mandatory. For muxless machines this should be a no-op. Returning 0
 * 	denotes success, anything else failure (in which case the switch is
 * 	aborted)
+ * @switch_ddc: switch DDC lines to given client.
+ * 	Optional. Should return the previous DDC owner on success or a
+ * 	negative int on failure
 * @power_state: cut or reinstate power of given client.
 * 	Optional. The return value is ignored
 * @get_client_id: determine if given pci device is integrated or discrete GPU.
@ -93,6 +116,7 @@ enum vga_switcheroo_client_id {
 struct vga_switcheroo_handler {
 	int (*init)(void);
 	int (*switchto)(enum vga_switcheroo_client_id id);
+	int (*switch_ddc)(enum vga_switcheroo_client_id id);
 	int (*power_state)(enum vga_switcheroo_client_id id,
 			   enum vga_switcheroo_state state);
 	enum vga_switcheroo_client_id (*get_client_id)(struct pci_dev *pdev);
@ -132,8 +156,12 @@ int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
 void vga_switcheroo_client_fb_set(struct pci_dev *dev,
 				  struct fb_info *info);

-int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler);
+int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
+				    enum vga_switcheroo_handler_flags_t handler_flags);
 void vga_switcheroo_unregister_handler(void);
+enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void);
+int vga_switcheroo_lock_ddc(struct pci_dev *pdev);
+int vga_switcheroo_unlock_ddc(struct pci_dev *pdev);

 int vga_switcheroo_process_delayed_switch(void);

@ -150,11 +178,15 @@ static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {}
 static inline int vga_switcheroo_register_client(struct pci_dev *dev,
 		const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return 0; }
 static inline void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info) {}
-static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler) { return 0; }
+static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler,
+		enum vga_switcheroo_handler_flags_t handler_flags) { return 0; }
 static inline int vga_switcheroo_register_audio_client(struct pci_dev *pdev,
 	const struct vga_switcheroo_client_ops *ops,
 	enum vga_switcheroo_client_id id) { return 0; }
 static inline void vga_switcheroo_unregister_handler(void) {}
+static inline enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return 0; }
+static inline int vga_switcheroo_lock_ddc(struct pci_dev *pdev) { return -ENODEV; }
+static inline int vga_switcheroo_unlock_ddc(struct pci_dev *pdev) { return -ENODEV; }
 static inline int vga_switcheroo_process_delayed_switch(void) { return 0; }
 static inline enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev) { return VGA_SWITCHEROO_ON; }

--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@ -669,6 +669,7 @@ struct drm_set_client_cap {
 	__u64 value;
 };

+#define DRM_RDWR O_RDWR
 #define DRM_CLOEXEC O_CLOEXEC
 struct drm_prime_handle {
 	__u32 handle;
--- a/include/uapi/linux/dma-buf.h
+++ b/include/uapi/linux/dma-buf.h
@ -0,0 +1,40 @@
+/*
+ * Framework for buffer objects that can be shared across devices/subsystems.
+ *
+ * Copyright(C) 2015 Intel Ltd
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _DMA_BUF_UAPI_H_
+#define _DMA_BUF_UAPI_H_
+
+#include <linux/types.h>
+
+/* begin/end dma-buf functions used for userspace mmap. */
+struct dma_buf_sync {
+	__u64 flags;
+};
+
+#define DMA_BUF_SYNC_READ      (1 << 0)
+#define DMA_BUF_SYNC_WRITE     (2 << 0)
+#define DMA_BUF_SYNC_RW        (DMA_BUF_SYNC_READ | DMA_BUF_SYNC_WRITE)
+#define DMA_BUF_SYNC_START     (0 << 2)
+#define DMA_BUF_SYNC_END       (1 << 2)
+#define DMA_BUF_SYNC_VALID_FLAGS_MASK \
+	(DMA_BUF_SYNC_RW | DMA_BUF_SYNC_END)
+
+#define DMA_BUF_BASE		'b'
+#define DMA_BUF_IOCTL_SYNC	_IOW(DMA_BUF_BASE, 0, struct dma_buf_sync)
+
+#endif