[Intel-gfx] [PATCH] drm/i915/psr: Kill scheduled work for Core platforms.

[Rodrigo Vivi]

The immediate enabling is actually not an issue for the
HW perspective for core platforms that have HW tracking.
HW will wait few identical idle frames before transitioning
to actual psr active anyways.

Note that this patch also remove the delayed activation
on HSW and BDW introduced by commit 'd0ac896a477d
("drm/i915: Delay first PSR activation.")'. This was
introduced to fix a blank screen on VLV/CHV and also
masked some frozen screens on other core platforms.
Probably the same that we are now properly hunting and fixing.

Furthermore, if we stop using delayed activation on core
platforms we will be able, on following up patches,
to use available workarounds to make HW tracking properly
exit PSR instead of the big nuke of disabling psr and
re-enable on exit and activate respectively.
At least on few reliable cases.

v2:(DK): Remove unnecessary WARN_ONs and make some other
	 VLV | CHV more readable.
v3: Do it regardless the timer rework.
v4: (DK/CI): Add VLV || CHV check on cancel work at psr_disable.

Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 17 +++++++++--------
 drivers/gpu/drm/i915/intel_psr.c    | 25 ++++++++++++++++---------
 2 files changed, 25 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index c4cc8fef11a0..f803b40848e8 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2568,15 +2568,11 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
 	seq_printf(m, "Active: %s\n", yesno(dev_priv->psr.active));
 	seq_printf(m, "Busy frontbuffer bits: 0x%03x\n",
 		   dev_priv->psr.busy_frontbuffer_bits);
-	seq_printf(m, "Re-enable work scheduled: %s\n",
-		   yesno(work_busy(&dev_priv->psr.work.work)));
 
-	if (HAS_DDI(dev_priv)) {
-		if (dev_priv->psr.psr2_support)
-			enabled = I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE;
-		else
-			enabled = I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE;
-	} else {
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
+		seq_printf(m, "Re-enable work scheduled: %s\n",
+			   yesno(work_busy(&dev_priv->psr.work.work)));
+
 		for_each_pipe(dev_priv, pipe) {
 			enum transcoder cpu_transcoder =
 				intel_pipe_to_cpu_transcoder(dev_priv, pipe);
@@ -2595,6 +2591,11 @@ static int i915_edp_psr_status(struct seq_file *m, void *data)
 
 			intel_display_power_put(dev_priv, power_domain);
 		}
+	} else {
+		if (dev_priv->psr.psr2_support)
+			enabled = I915_READ(EDP_PSR2_CTL) & EDP_PSR2_ENABLE;
+		else
+			enabled = I915_READ(EDP_PSR_CTL) & EDP_PSR_ENABLE;
 	}
 
 	seq_printf(m, "Main link in standby mode: %s\n",
diff --git a/drivers/gpu/drm/i915/intel_psr.c b/drivers/gpu/drm/i915/intel_psr.c
index 975ebb51c7af..d93ecfc5d739 100644
--- a/drivers/gpu/drm/i915/intel_psr.c
+++ b/drivers/gpu/drm/i915/intel_psr.c
@@ -652,9 +652,7 @@ void intel_psr_enable(struct intel_dp *intel_dp,
 	dev_priv->psr.enable_source(intel_dp, crtc_state);
 	dev_priv->psr.enabled = intel_dp;
 
-	if (INTEL_GEN(dev_priv) >= 9) {
-		intel_psr_activate(intel_dp);
-	} else {
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
 		/*
 		 * FIXME: Activation should happen immediately since this
 		 * function is just called after pipe is fully trained and
@@ -667,6 +665,8 @@ void intel_psr_enable(struct intel_dp *intel_dp,
 		 */
 		schedule_delayed_work(&dev_priv->psr.work,
 				      msecs_to_jiffies(intel_dp->panel_power_cycle_delay * 5));
+	} else {
+		intel_psr_activate(intel_dp);
 	}
 
 unlock:
@@ -786,7 +786,8 @@ void intel_psr_disable(struct intel_dp *intel_dp,
 	dev_priv->psr.enabled = NULL;
 	mutex_unlock(&dev_priv->psr.lock);
 
-	cancel_delayed_work_sync(&dev_priv->psr.work);
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+		cancel_delayed_work_sync(&dev_priv->psr.work);
 }
 
 static void intel_psr_work(struct work_struct *work)
@@ -1045,10 +1046,15 @@ void intel_psr_flush(struct drm_i915_private *dev_priv,
 		}
 	}
 
-	if (!dev_priv->psr.active && !dev_priv->psr.busy_frontbuffer_bits)
-		if (!work_busy(&dev_priv->psr.work.work))
-			schedule_delayed_work(&dev_priv->psr.work,
-					      msecs_to_jiffies(100));
+	if (!dev_priv->psr.active && !dev_priv->psr.busy_frontbuffer_bits) {
+		if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
+			if (!work_busy(&dev_priv->psr.work.work))
+				schedule_delayed_work(&dev_priv->psr.work,
+						      msecs_to_jiffies(100));
+		} else {
+			intel_psr_activate(dev_priv->psr.enabled);
+		}
+	}
 	mutex_unlock(&dev_priv->psr.lock);
 }
 
@@ -1095,7 +1101,8 @@ void intel_psr_init(struct drm_i915_private *dev_priv)
 		dev_priv->psr.link_standby = false;
 	}
 
-	INIT_DELAYED_WORK(&dev_priv->psr.work, intel_psr_work);
+	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
+		INIT_DELAYED_WORK(&dev_priv->psr.work, intel_psr_work);
 	mutex_init(&dev_priv->psr.lock);
 
 	if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
-- 
2.13.6