On 2021-02-09 10:24, quanyang.wang@windriver.com wrote:

From: Quanyang Wang quanyang.wang@windriver.com

When run xrandr to change resolution on Beaglebone Black board, it will print the error information:

root@beaglebone:~# xrandr -display :0 --output HDMI-1 --mode 720x400 [drm:drm_crtc_commit_wait] *ERROR* flip_done timed out [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CRTC:32:tilcdc crtc] commit wait timed out [drm:drm_crtc_commit_wait] *ERROR* flip_done timed out [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [CONNECTOR:34:HDMI-A-1] commit wait timed out [drm:drm_crtc_commit_wait] *ERROR* flip_done timed out [drm:drm_atomic_helper_wait_for_dependencies] *ERROR* [PLANE:31:plane-0] commit wait timed out tilcdc 4830e000.lcdc: already pending page flip!

This is because there is operation sequence as below:

drm_atomic_connector_commit_dpms(mode is DRM_MODE_DPMS_OFF): ... drm_atomic_helper_setup_commit <- init_completion(commit_A->flip_done) drm_atomic_helper_commit_tail tilcdc_crtc_atomic_disable tilcdc_plane_atomic_update <- drm_crtc_send_vblank_event in tilcdc_crtc_irq is skipped since tilcdc_crtc->enabled is 0 tilcdc_crtc_atomic_flush <- drm_crtc_send_vblank_event is skipped since crtc->state->event is set to be NULL in tilcdc_plane_atomic_update drm_mode_setcrtc: ... drm_atomic_helper_setup_commit <- init_completion(commit_B->flip_done) drm_atomic_helper_wait_for_dependencies drm_crtc_commit_wait <- wait for commit_A->flip_done completing

Just as shown above, the steps which could complete commit_A->flip_done are all skipped and commit_A->flip_done will never be completed. This will result a time-out ERROR when drm_crtc_commit_wait check the commit_A->flip_done. So add drm_crtc_send_vblank_event in tilcdc_crtc_atomic_disable to complete commit_A->flip_done.

Fixes: cb345decb4d2 ("drm/tilcdc: Use standard drm_atomic_helper_commit") Signed-off-by: Quanyang Wang quanyang.wang@windriver.com

Reviewed-by: Jyri Sarha jyri.sarha@iki.fi Tested-by: Jyri Sarha jyri.sarha@iki.fi

Thanks a lot! I think I have bumbed into this once or twice, but latelu I have had time to look into this. I'll merge this to drm-misc-next soon.

Best regards, Jyri

---

drivers/gpu/drm/tilcdc/tilcdc_crtc.c | 9 +++++++++ 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c index 30213708fc99..d99afd19ca08 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_crtc.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_crtc.c @@ -515,6 +515,15 @@ static void tilcdc_crtc_off(struct drm_crtc *crtc, bool shutdown)

drm_crtc_vblank_off(crtc);

• spin_lock_irq(&crtc->dev->event_lock);

• if (crtc->state->event) {

• drm_crtc_send_vblank_event(crtc, crtc->state->event);
  

• crtc->state->event = NULL;
  

• }

• spin_unlock_irq(&crtc->dev->event_lock);

• tilcdc_crtc_disable_irqs(dev);

  pm_runtime_put_sync(dev->dev);