drm/i915/psr: Force PSR probe only after full initialization

Commit 60c6a14b48 ("drm/i915/display: Force the state compute phase
once to enable PSR") was forcing the state compute too earlier
causing errors because not everything was initialized, so here
moving to the end of i915_driver_modeset_probe() when the display is
all initialized.

Also fixing the place where it disarm the force probe as during the
atomic check phase errors could happen like the ones due locking and
it would cause PSR to never be enabled if that happens.
Leaving the disarm to the atomic commit phase, intel_psr_enable() or
intel_psr_update() will be called even if the current state do not
allow PSR to be enabled.

v2: Check if intel_dp is null in intel_psr_force_mode_changed_set()
v3: Check intel_dp before get dev_priv
v4:
- renamed intel_psr_force_mode_changed_set() to
intel_psr_set_force_mode_changed()
- removed the set parameter from intel_psr_set_force_mode_changed()
- not calling intel_psr_set_force_mode_changed() from
intel_psr_enable/update(), directly setting it after the same checks
that intel_psr_set_force_mode_changed() does
- moved intel_psr_set_force_mode_changed() arm call to
i915_driver_modeset_probe() as it is a better for a PSR call, all the
functions calls happening between the old and the new function call
will cause issue

[backported to v5.6-rc3]

Fixes: 60c6a14b48 ("drm/i915/display: Force the state compute phase once to enable PSR")
Closes: https://gitlab.freedesktop.org/drm/intel/issues/1151
Tested-by: Ross Zwisler <zwisler@google.com>
Reported-by: Ross Zwisler <zwisler@google.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200221212635.11614-1-jose.souza@intel.com
Link: https://patchwork.freedesktop.org/patch/msgid/20200227205540.126135-1-jose.souza@intel.com
(cherry picked from commit df1a5bfc16)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

drivers/gpu/drm/i915/display/intel_psr.c

@@ -852,10 +852,12 @@ void intel_psr_enable(struct intel_dp *intel_dp,
 {
 	struct drm_i915_private *dev_priv = dp_to_i915(intel_dp);
 
-	if (!crtc_state->has_psr)
+	if (!CAN_PSR(dev_priv) || dev_priv->psr.dp != intel_dp)
 		return;
 
-	if (WARN_ON(!CAN_PSR(dev_priv)))
+	dev_priv->psr.force_mode_changed = false;
+
+	if (!crtc_state->has_psr)
 		return;
 
 	WARN_ON(dev_priv->drrs.dp);
@@ -1009,6 +1011,8 @@ void intel_psr_update(struct intel_dp *intel_dp,
 	if (!CAN_PSR(dev_priv) || READ_ONCE(psr->dp) != intel_dp)
 		return;
 
+	dev_priv->psr.force_mode_changed = false;
+
 	mutex_lock(&dev_priv->psr.lock);
 
 	enable = crtc_state->has_psr && psr_global_enabled(psr->debug);
@@ -1534,7 +1538,7 @@ void intel_psr_atomic_check(struct drm_connector *connector,
 	struct drm_crtc_state *crtc_state;
 
 	if (!CAN_PSR(dev_priv) || !new_state->crtc ||
-	    dev_priv->psr.initially_probed)
+	    !dev_priv->psr.force_mode_changed)
 		return;
 
 	intel_connector = to_intel_connector(connector);
@@ -1545,5 +1549,18 @@ void intel_psr_atomic_check(struct drm_connector *connector,
 	crtc_state = drm_atomic_get_new_crtc_state(new_state->state,
 						   new_state->crtc);
 	crtc_state->mode_changed = true;
-	dev_priv->psr.initially_probed = true;
+}
+
+void intel_psr_set_force_mode_changed(struct intel_dp *intel_dp)
+{
+	struct drm_i915_private *dev_priv;
+
+	if (!intel_dp)
+		return;
+
+	dev_priv = dp_to_i915(intel_dp);
+	if (!CAN_PSR(dev_priv) || intel_dp != dev_priv->psr.dp)
+		return;
+
+	dev_priv->psr.force_mode_changed = true;
 }

drivers/gpu/drm/i915/display/intel_psr.h

@@ -40,5 +40,6 @@ bool intel_psr_enabled(struct intel_dp *intel_dp);
 void intel_psr_atomic_check(struct drm_connector *connector,
 			    struct drm_connector_state *old_state,
 			    struct drm_connector_state *new_state);
+void intel_psr_set_force_mode_changed(struct intel_dp *intel_dp);
 
 #endif /* __INTEL_PSR_H__ */

drivers/gpu/drm/i915/i915_drv.c

@@ -56,6 +56,7 @@
 #include "display/intel_hotplug.h"
 #include "display/intel_overlay.h"
 #include "display/intel_pipe_crc.h"
+#include "display/intel_psr.h"
 #include "display/intel_sprite.h"
 #include "display/intel_vga.h"
 
@@ -330,6 +331,8 @@ static int i915_driver_modeset_probe(struct drm_i915_private *i915)
 
 	intel_init_ipc(i915);
 
+	intel_psr_set_force_mode_changed(i915->psr.dp);
+
 	return 0;
 
 cleanup_gem:

drivers/gpu/drm/i915/i915_drv.h

@@ -505,7 +505,7 @@ struct i915_psr {
 	bool dc3co_enabled;
 	u32 dc3co_exit_delay;
 	struct delayed_work idle_work;
-	bool initially_probed;
+	bool force_mode_changed;
 };
 
 #define QUIRK_LVDS_SSC_DISABLE (1<<1)