usb: fixes for v4.9-rc2

First set of fixes for v4.9-rc cycle. Nothing major
 this time around. The most important patches are the
 3 fixes in dwc3 (dma_free_coheren() size fix,
 queued request accounting fix and Isochronous
 StartTransfer fix) and the 3 reverts on dwc2.
 
 We're also including the late atmel UDC fix which
 didn't make it into v4.8-final.
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Merge tag 'fixes-for-v4.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/balbi/usb into usb-linus

Felipe writes:

usb: fixes for v4.9-rc2

First set of fixes for v4.9-rc cycle. Nothing major
this time around. The most important patches are the
3 fixes in dwc3 (dma_free_coheren() size fix,
queued request accounting fix and Isochronous
StartTransfer fix) and the 3 reverts on dwc2.

We're also including the late atmel UDC fix which
didn't make it into v4.8-final.

Documentation/devicetree/bindings/usb/dwc2.txt

@@ -28,10 +28,7 @@ Refer to phy/phy-bindings.txt for generic phy consumer properties
 - g-use-dma: enable dma usage in gadget driver.
 - g-rx-fifo-size: size of rx fifo size in gadget mode.
 - g-np-tx-fifo-size: size of non-periodic tx fifo size in gadget mode.
-
-Deprecated properties:
-- g-tx-fifo-size: size of periodic tx fifo per endpoint (except ep0)
-  in gadget mode.
+- g-tx-fifo-size: size of periodic tx fifo per endpoint (except ep0) in gadget mode.
 
 Example:
 

drivers/usb/dwc2/core.c

@@ -463,9 +463,18 @@ static void dwc2_clear_force_mode(struct dwc2_hsotg *hsotg)
  */
 void dwc2_force_dr_mode(struct dwc2_hsotg *hsotg)
 {
+	bool ret;
+
 	switch (hsotg->dr_mode) {
 	case USB_DR_MODE_HOST:
-		dwc2_force_mode(hsotg, true);
+		ret = dwc2_force_mode(hsotg, true);
+		/*
+		 * NOTE: This is required for some rockchip soc based
+		 * platforms on their host-only dwc2.
+		 */
+		if (!ret)
+			msleep(50);
+
 		break;
 	case USB_DR_MODE_PERIPHERAL:
 		dwc2_force_mode(hsotg, false);

drivers/usb/dwc2/core.h

@@ -259,6 +259,13 @@ enum dwc2_lx_state {
 	DWC2_L3,	/* Off state */
 };
 
+/*
+ * Gadget periodic tx fifo sizes as used by legacy driver
+ * EP0 is not included
+ */
+#define DWC2_G_P_LEGACY_TX_FIFO_SIZE {256, 256, 256, 256, 768, 768, 768, \
+					   768, 0, 0, 0, 0, 0, 0, 0}
+
 /* Gadget ep0 states */
 enum dwc2_ep0_state {
 	DWC2_EP0_SETUP,

drivers/usb/dwc2/gadget.c

@@ -186,10 +186,9 @@ static void dwc2_hsotg_ctrl_epint(struct dwc2_hsotg *hsotg,
  */
 static void dwc2_hsotg_init_fifo(struct dwc2_hsotg *hsotg)
 {
-	unsigned int fifo;
+	unsigned int ep;
 	unsigned int addr;
 	int timeout;
-	u32 dptxfsizn;
 	u32 val;
 
 	/* Reset fifo map if not correctly cleared during previous session */
@@ -217,16 +216,16 @@ static void dwc2_hsotg_init_fifo(struct dwc2_hsotg *hsotg)
 	 * them to endpoints dynamically according to maxpacket size value of
 	 * given endpoint.
 	 */
-	for (fifo = 1; fifo < MAX_EPS_CHANNELS; fifo++) {
-		dptxfsizn = dwc2_readl(hsotg->regs + DPTXFSIZN(fifo));
+	for (ep = 1; ep < MAX_EPS_CHANNELS; ep++) {
+		if (!hsotg->g_tx_fifo_sz[ep])
+			continue;
+		val = addr;
+		val |= hsotg->g_tx_fifo_sz[ep] << FIFOSIZE_DEPTH_SHIFT;
+		WARN_ONCE(addr + hsotg->g_tx_fifo_sz[ep] > hsotg->fifo_mem,
+			  "insufficient fifo memory");
+		addr += hsotg->g_tx_fifo_sz[ep];
 
-		val = (dptxfsizn & FIFOSIZE_DEPTH_MASK) | addr;
-		addr += dptxfsizn >> FIFOSIZE_DEPTH_SHIFT;
-
-		if (addr > hsotg->fifo_mem)
-			break;
-
-		dwc2_writel(val, hsotg->regs + DPTXFSIZN(fifo));
+		dwc2_writel(val, hsotg->regs + DPTXFSIZN(ep));
 	}
 
 	/*
@@ -3807,10 +3806,36 @@ static void dwc2_hsotg_dump(struct dwc2_hsotg *hsotg)
 static void dwc2_hsotg_of_probe(struct dwc2_hsotg *hsotg)
 {
 	struct device_node *np = hsotg->dev->of_node;
+	u32 len = 0;
+	u32 i = 0;
 
 	/* Enable dma if requested in device tree */
 	hsotg->g_using_dma = of_property_read_bool(np, "g-use-dma");
 
+	/*
+	* Register TX periodic fifo size per endpoint.
+	* EP0 is excluded since it has no fifo configuration.
+	*/
+	if (!of_find_property(np, "g-tx-fifo-size", &len))
+		goto rx_fifo;
+
+	len /= sizeof(u32);
+
+	/* Read tx fifo sizes other than ep0 */
+	if (of_property_read_u32_array(np, "g-tx-fifo-size",
+						&hsotg->g_tx_fifo_sz[1], len))
+		goto rx_fifo;
+
+	/* Add ep0 */
+	len++;
+
+	/* Make remaining TX fifos unavailable */
+	if (len < MAX_EPS_CHANNELS) {
+		for (i = len; i < MAX_EPS_CHANNELS; i++)
+			hsotg->g_tx_fifo_sz[i] = 0;
+	}
+
+rx_fifo:
 	/* Register RX fifo size */
 	of_property_read_u32(np, "g-rx-fifo-size", &hsotg->g_rx_fifo_sz);
 
@@ -3832,10 +3857,13 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
 	struct device *dev = hsotg->dev;
 	int epnum;
 	int ret;
+	int i;
+	u32 p_tx_fifo[] = DWC2_G_P_LEGACY_TX_FIFO_SIZE;
 
 	/* Initialize to legacy fifo configuration values */
 	hsotg->g_rx_fifo_sz = 2048;
 	hsotg->g_np_g_tx_fifo_sz = 1024;
+	memcpy(&hsotg->g_tx_fifo_sz[1], p_tx_fifo, sizeof(p_tx_fifo));
 	/* Device tree specific probe */
 	dwc2_hsotg_of_probe(hsotg);
 
@@ -3853,6 +3881,9 @@ int dwc2_gadget_init(struct dwc2_hsotg *hsotg, int irq)
 	dev_dbg(dev, "NonPeriodic TXFIFO size: %d\n",
 						hsotg->g_np_g_tx_fifo_sz);
 	dev_dbg(dev, "RXFIFO size: %d\n", hsotg->g_rx_fifo_sz);
+	for (i = 0; i < MAX_EPS_CHANNELS; i++)
+		dev_dbg(dev, "Periodic TXFIFO%2d size: %d\n", i,
+						hsotg->g_tx_fifo_sz[i]);
 
 	hsotg->gadget.max_speed = USB_SPEED_HIGH;
 	hsotg->gadget.ops = &dwc2_hsotg_gadget_ops;

drivers/usb/dwc3/gadget.c

@@ -783,6 +783,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 		req->trb = trb;
 		req->trb_dma = dwc3_trb_dma_offset(dep, trb);
 		req->first_trb_index = dep->trb_enqueue;
+		dep->queued_requests++;
 	}
 
 	dwc3_ep_inc_enq(dep);
@@ -833,8 +834,6 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
 
 	trb->ctrl |= DWC3_TRB_CTRL_HWO;
 
-	dep->queued_requests++;
-
 	trace_dwc3_prepare_trb(dep, trb);
 }
 
@@ -1074,9 +1073,17 @@ static int __dwc3_gadget_ep_queue(struct dwc3_ep *dep, struct dwc3_request *req)
 
 	list_add_tail(&req->list, &dep->pending_list);
 
-	if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
-			dep->flags & DWC3_EP_PENDING_REQUEST) {
-		if (list_empty(&dep->started_list)) {
+	/*
+	 * NOTICE: Isochronous endpoints should NEVER be prestarted. We must
+	 * wait for a XferNotReady event so we will know what's the current
+	 * (micro-)frame number.
+	 *
+	 * Without this trick, we are very, very likely gonna get Bus Expiry
+	 * errors which will force us issue EndTransfer command.
+	 */
+	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
+		if ((dep->flags & DWC3_EP_PENDING_REQUEST) &&
+				list_empty(&dep->started_list)) {
 			dwc3_stop_active_transfer(dwc, dep->number, true);
 			dep->flags = DWC3_EP_ENABLED;
 		}
@@ -1861,8 +1868,11 @@ static int __dwc3_cleanup_done_trbs(struct dwc3 *dwc, struct dwc3_ep *dep,
 	unsigned int		s_pkt = 0;
 	unsigned int		trb_status;
 
-	dep->queued_requests--;
 	dwc3_ep_inc_deq(dep);
+
+	if (req->trb == trb)
+		dep->queued_requests--;
+
 	trace_dwc3_complete_trb(dep, trb);
 
 	/*
@@ -2980,7 +2990,7 @@ err3:
 	kfree(dwc->setup_buf);
 
 err2:
-	dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
+	dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb) * 2,
 			dwc->ep0_trb, dwc->ep0_trb_addr);
 
 err1:
@@ -3005,7 +3015,7 @@ void dwc3_gadget_exit(struct dwc3 *dwc)
 	kfree(dwc->setup_buf);
 	kfree(dwc->zlp_buf);
 
-	dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb),
+	dma_free_coherent(dwc->dev, sizeof(*dwc->ep0_trb) * 2,
 			dwc->ep0_trb, dwc->ep0_trb_addr);
 
 	dma_free_coherent(dwc->dev, sizeof(*dwc->ctrl_req),

drivers/usb/gadget/function/f_fs.c

@@ -136,8 +136,60 @@ struct ffs_epfile {
 	/*
 	 * Buffer for holding data from partial reads which may happen since
 	 * we’re rounding user read requests to a multiple of a max packet size.
+	 *
+	 * The pointer is initialised with NULL value and may be set by
+	 * __ffs_epfile_read_data function to point to a temporary buffer.
+	 *
+	 * In normal operation, calls to __ffs_epfile_read_buffered will consume
+	 * data from said buffer and eventually free it.  Importantly, while the
+	 * function is using the buffer, it sets the pointer to NULL.  This is
+	 * all right since __ffs_epfile_read_data and __ffs_epfile_read_buffered
+	 * can never run concurrently (they are synchronised by epfile->mutex)
+	 * so the latter will not assign a new value to the pointer.
+	 *
+	 * Meanwhile ffs_func_eps_disable frees the buffer (if the pointer is
+	 * valid) and sets the pointer to READ_BUFFER_DROP value.  This special
+	 * value is crux of the synchronisation between ffs_func_eps_disable and
+	 * __ffs_epfile_read_data.
+	 *
+	 * Once __ffs_epfile_read_data is about to finish it will try to set the
+	 * pointer back to its old value (as described above), but seeing as the
+	 * pointer is not-NULL (namely READ_BUFFER_DROP) it will instead free
+	 * the buffer.
+	 *
+	 * == State transitions ==
+	 *
+	 * • ptr == NULL:  (initial state)
+	 *   ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP
+	 *   ◦ __ffs_epfile_read_buffered:    nop
+	 *   ◦ __ffs_epfile_read_data allocates temp buffer: go to ptr == buf
+	 *   ◦ reading finishes:              n/a, not in ‘and reading’ state
+	 * • ptr == DROP:
+	 *   ◦ __ffs_epfile_read_buffer_free: nop
+	 *   ◦ __ffs_epfile_read_buffered:    go to ptr == NULL
+	 *   ◦ __ffs_epfile_read_data allocates temp buffer: free buf, nop
+	 *   ◦ reading finishes:              n/a, not in ‘and reading’ state
+	 * • ptr == buf:
+	 *   ◦ __ffs_epfile_read_buffer_free: free buf, go to ptr == DROP
+	 *   ◦ __ffs_epfile_read_buffered:    go to ptr == NULL and reading
+	 *   ◦ __ffs_epfile_read_data:        n/a, __ffs_epfile_read_buffered
+	 *                                    is always called first
+	 *   ◦ reading finishes:              n/a, not in ‘and reading’ state
+	 * • ptr == NULL and reading:
+	 *   ◦ __ffs_epfile_read_buffer_free: go to ptr == DROP and reading
+	 *   ◦ __ffs_epfile_read_buffered:    n/a, mutex is held
+	 *   ◦ __ffs_epfile_read_data:        n/a, mutex is held
+	 *   ◦ reading finishes and …
+	 *     … all data read:               free buf, go to ptr == NULL
+	 *     … otherwise:                   go to ptr == buf and reading
+	 * • ptr == DROP and reading:
+	 *   ◦ __ffs_epfile_read_buffer_free: nop
+	 *   ◦ __ffs_epfile_read_buffered:    n/a, mutex is held
+	 *   ◦ __ffs_epfile_read_data:        n/a, mutex is held
+	 *   ◦ reading finishes:              free buf, go to ptr == DROP
 	 */
-	struct ffs_buffer		*read_buffer;	/* P: epfile->mutex */
+	struct ffs_buffer		*read_buffer;
+#define READ_BUFFER_DROP ((struct ffs_buffer *)ERR_PTR(-ESHUTDOWN))
 
 	char				name[5];
 
@@ -736,25 +788,47 @@ static void ffs_epfile_async_io_complete(struct usb_ep *_ep,
 	schedule_work(&io_data->work);
 }
 
+static void __ffs_epfile_read_buffer_free(struct ffs_epfile *epfile)
+{
+	/*
+	 * See comment in struct ffs_epfile for full read_buffer pointer
+	 * synchronisation story.
+	 */
+	struct ffs_buffer *buf = xchg(&epfile->read_buffer, READ_BUFFER_DROP);
+	if (buf && buf != READ_BUFFER_DROP)
+		kfree(buf);
+}
+
 /* Assumes epfile->mutex is held. */
 static ssize_t __ffs_epfile_read_buffered(struct ffs_epfile *epfile,
 					  struct iov_iter *iter)
 {
-	struct ffs_buffer *buf = epfile->read_buffer;
+	/*
+	 * Null out epfile->read_buffer so ffs_func_eps_disable does not free
+	 * the buffer while we are using it.  See comment in struct ffs_epfile
+	 * for full read_buffer pointer synchronisation story.
+	 */
+	struct ffs_buffer *buf = xchg(&epfile->read_buffer, NULL);
 	ssize_t ret;
-	if (!buf)
+	if (!buf || buf == READ_BUFFER_DROP)
 		return 0;
 
 	ret = copy_to_iter(buf->data, buf->length, iter);
 	if (buf->length == ret) {
 		kfree(buf);
-		epfile->read_buffer = NULL;
-	} else if (unlikely(iov_iter_count(iter))) {
+		return ret;
+	}
+
+	if (unlikely(iov_iter_count(iter))) {
 		ret = -EFAULT;
 	} else {
 		buf->length -= ret;
 		buf->data += ret;
 	}
+
+	if (cmpxchg(&epfile->read_buffer, NULL, buf))
+		kfree(buf);
+
 	return ret;
 }
 
@@ -783,7 +857,15 @@ static ssize_t __ffs_epfile_read_data(struct ffs_epfile *epfile,
 	buf->length = data_len;
 	buf->data = buf->storage;
 	memcpy(buf->storage, data + ret, data_len);
-	epfile->read_buffer = buf;
+
+	/*
+	 * At this point read_buffer is NULL or READ_BUFFER_DROP (if
+	 * ffs_func_eps_disable has been called in the meanwhile).  See comment
+	 * in struct ffs_epfile for full read_buffer pointer synchronisation
+	 * story.
+	 */
+	if (unlikely(cmpxchg(&epfile->read_buffer, NULL, buf)))
+		kfree(buf);
 
 	return ret;
 }
@@ -1097,8 +1179,7 @@ ffs_epfile_release(struct inode *inode, struct file *file)
 
 	ENTER();
 
-	kfree(epfile->read_buffer);
-	epfile->read_buffer = NULL;
+	__ffs_epfile_read_buffer_free(epfile);
 	ffs_data_closed(epfile->ffs);
 
 	return 0;
@@ -1724,24 +1805,20 @@ static void ffs_func_eps_disable(struct ffs_function *func)
 	unsigned count            = func->ffs->eps_count;
 	unsigned long flags;
 
+	spin_lock_irqsave(&func->ffs->eps_lock, flags);
 	do {
-		if (epfile)
-			mutex_lock(&epfile->mutex);
-		spin_lock_irqsave(&func->ffs->eps_lock, flags);
 		/* pending requests get nuked */
 		if (likely(ep->ep))
 			usb_ep_disable(ep->ep);
 		++ep;
-		spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
 
 		if (epfile) {
 			epfile->ep = NULL;
-			kfree(epfile->read_buffer);
-			epfile->read_buffer = NULL;
-			mutex_unlock(&epfile->mutex);
+			__ffs_epfile_read_buffer_free(epfile);
 			++epfile;
 		}
 	} while (--count);
+	spin_unlock_irqrestore(&func->ffs->eps_lock, flags);
 }
 
 static int ffs_func_eps_enable(struct ffs_function *func)

drivers/usb/gadget/function/u_ether.c

@@ -590,8 +590,9 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
 
 	/* throttle high/super speed IRQ rate back slightly */
 	if (gadget_is_dualspeed(dev->gadget))
-		req->no_interrupt = (dev->gadget->speed == USB_SPEED_HIGH ||
-				     dev->gadget->speed == USB_SPEED_SUPER)
+		req->no_interrupt = (((dev->gadget->speed == USB_SPEED_HIGH ||
+				       dev->gadget->speed == USB_SPEED_SUPER)) &&
+					!list_empty(&dev->tx_reqs))
 			? ((atomic_read(&dev->tx_qlen) % dev->qmult) != 0)
 			: 0;
 

drivers/usb/gadget/udc/atmel_usba_udc.c

@@ -1978,7 +1978,7 @@ static struct usba_ep * atmel_udc_of_init(struct platform_device *pdev,
 			dev_err(&pdev->dev, "of_probe: name error(%d)\n", ret);
 			goto err;
 		}
-		ep->ep.name = name;
+		ep->ep.name = kasprintf(GFP_KERNEL, "ep%d", ep->index);
 
 		ep->ep_regs = udc->regs + USBA_EPT_BASE(i);
 		ep->dma_regs = udc->regs + USBA_DMA_BASE(i);