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* [PATCH] drm/i915/edp: Read link status after exit PSR
@ 2017-04-27 14:35 Lee, Shawn C
  2017-04-27 14:16 ` Chris Wilson
                   ` (6 more replies)
  0 siblings, 7 replies; 13+ messages in thread
From: Lee, Shawn C @ 2017-04-27 14:35 UTC (permalink / raw)
  To: intel-gfx; +Cc: Cooper Chiou, Jim Bride, Jani Nikula, Rodrigo Vivi, Ryan Lin

From: "Lee, Shawn C" <shawn.c.lee@intel.com>

Display driver read DPCD register 0x202, 0x203 and 0x204 to identify
eDP sink status. If PSR exit is ongoing at eDP sink, and eDP source
read these registers at the same time. Panel will report EQ & symbol
lock not done. It will cause panel display flicking.
So driver have to make sure PSR already exit before read link status.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99639
TEST=Reboot DUT and no flicking on local display at login screen

Cc: Cooper Chiou <cooper.chiou@intel.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Jim Bride <jim.bride@intel.com>
Cc: Ryan Lin <ryan.lin@intel.com>

Signed-off-by: Shawn Lee <shawn.c.lee@intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c |   34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 08834f74d396..cc431337b2dc 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -4252,19 +4252,35 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
 }
 
 static void
+intel_edp_wait_PSR_exit(struct intel_dp *intel_dp)
+{
+	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 srd_status, count = 100;
+
+	while (count--) {
+		srd_status = I915_READ(EDP_PSR_STATUS_CTL);
+
+		if ((srd_status & EDP_PSR_STATUS_SENDING_TP1) ||
+		    (srd_status & EDP_PSR_STATUS_SENDING_TP2_TP3) ||
+		    (srd_status & EDP_PSR_STATUS_SENDING_IDLE) ||
+		    (srd_status & EDP_PSR_STATUS_AUX_SENDING)) {
+			usleep_range(100, 150);
+		} else
+			return;
+	}
+}
+
+static void
 intel_dp_check_link_status(struct intel_dp *intel_dp)
 {
 	struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base;
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	u8 link_status[DP_LINK_STATUS_SIZE];
 
 	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
 
-	if (!intel_dp_get_link_status(intel_dp, link_status)) {
-		DRM_ERROR("Failed to get link status\n");
-		return;
-	}
-
 	if (!intel_encoder->base.crtc)
 		return;
 
@@ -4278,6 +4294,14 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp)
 	if (!intel_dp_link_params_valid(intel_dp))
 		return;
 
+	if (is_edp(intel_dp) && dev_priv->psr.enabled)
+		intel_edp_wait_PSR_exit(intel_dp);
+
+	if (!intel_dp_get_link_status(intel_dp, link_status)) {
+		DRM_ERROR("Failed to get link status\n");
+		return;
+	}
+
 	/* Retrain if Channel EQ or CR not ok */
 	if (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) {
 		DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n",
-- 
1.7.9.5

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^ permalink raw reply related	[flat|nested] 13+ messages in thread

end of thread, other threads:[~2017-05-05  6:38 UTC | newest]

Thread overview: 13+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-04-27 14:35 [PATCH] drm/i915/edp: Read link status after exit PSR Lee, Shawn C
2017-04-27 14:16 ` Chris Wilson
2017-04-27 14:38 ` Ville Syrjälä
2017-04-28  3:08   ` Lee, Shawn C
2017-04-28 11:11     ` Ville Syrjälä
2017-05-03  7:06       ` Lee, Shawn C
2017-04-27 14:46 ` ✓ Fi.CI.BAT: success for " Patchwork
2017-04-28  9:58 ` [PATCH v2] drm/i915/edp: Read link status after exit link training Lee, Shawn C
2017-04-28 11:50   ` Tvrtko Ursulin
2017-05-03  7:42     ` Lee, Shawn C
2017-04-28 11:19 ` ✓ Fi.CI.BAT: success for drm/i915/edp: Read link status after exit PSR (rev2) Patchwork
2017-05-05  6:38 ` ✓ Fi.CI.BAT: success for drm/i915/edp: Read link status after exit PSR (rev3) Patchwork
2017-05-05  6:50 ` [PATCH v3] drm/i915/edp: Read link status after exit link training Lee, Shawn C

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