Re: [v1] drm/msm/disp/dpu1: avoid perf update in frame done event

[Doug Anderson]

Hi,

On Wed, May 26, 2021 at 10:08 PM Krishna Manikandan
<mkrishn@xxxxxxxxxxxxxx> wrote:
>
> Crtc perf update from frame event work can result in
> wrong bandwidth and clock update from dpu if the work
> is scheduled after the swap state has happened.
>
> Avoid such issues by moving perf update to complete
> commit once the frame is accepted by the hardware.
>
> Fixes: a29c8c024165 ("drm/msm/disp/dpu1: fix display underruns during modeset")
> Signed-off-by: Krishna Manikandan <mkrishn@xxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)

I don't know much about this code or any of the theory behind it, but
I can confirm that this fixes the hang I was seeing with the previous
patch. On sc7180-trogdor-lazor:

Tested-by: Douglas Anderson <dianders@xxxxxxxxxxxx>