[PATCH 4/4] drm/msm: dpu: Don't queue the frame_done watchdog for cursor

[Sean Paul]

From: Sean Paul <seanpaul at chromium.org>

In the case of an async/cursor update, we don't wait for the frame_done
event, which means handle_frame_done is never called, and the frame_done
watchdog isn't canceled. Currently, this results in a frame_done timeout
every time the cursor moves without a synchronous frame following it up
before the timeout expires. Since we don't wait for frame_done, and
don't handle it, we shouldn't modify the watchdog.

Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
 drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
index 51e46b206c73e..05145cf9fb408 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder.c
@@ -1794,7 +1794,6 @@ void dpu_encoder_kickoff(struct drm_encoder *drm_enc, bool async)
 {
 	struct dpu_encoder_virt *dpu_enc;
 	struct dpu_encoder_phys *phys;
-	unsigned long timeout_ms;
 	ktime_t wakeup_time;
 	unsigned int i;
 
@@ -1807,12 +1806,20 @@ void dpu_encoder_kickoff(struct drm_encoder *drm_enc, bool async)
 
 	trace_dpu_enc_kickoff(DRMID(drm_enc));
 
-	timeout_ms = DPU_ENCODER_FRAME_DONE_TIMEOUT_FRAMES * 1000 /
-		drm_mode_vrefresh(&drm_enc->crtc->state->adjusted_mode);
+	/*
+	 * Asynchronous frames don't handle FRAME_DONE events. As such, they
+	 * shouldn't enable the frame_done watchdog since it will always time
+	 * out.
+	 */
+	if (!async) {
+		unsigned long timeout_ms;
+		timeout_ms = DPU_ENCODER_FRAME_DONE_TIMEOUT_FRAMES * 1000 /
+			drm_mode_vrefresh(&drm_enc->crtc->state->adjusted_mode);
 
-	atomic_set(&dpu_enc->frame_done_timeout_ms, timeout_ms);
-	mod_timer(&dpu_enc->frame_done_timer,
-		  jiffies + msecs_to_jiffies(timeout_ms));
+		atomic_set(&dpu_enc->frame_done_timeout_ms, timeout_ms);
+		mod_timer(&dpu_enc->frame_done_timer,
+			  jiffies + msecs_to_jiffies(timeout_ms));
+	}
 
 	/* All phys encs are ready to go, trigger the kickoff */
 	_dpu_encoder_kickoff_phys(dpu_enc, async);
-- 
Sean Paul, Software Engineer, Google / Chromium OS