Re: [PATCH 2/9] drm/msm/dpu: add real wait_for_commit_done()

[Sean Paul]

On Tue, Aug 27, 2019 at 02:33:32PM -0700, Rob Clark wrote:
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
> 
> Just waiting for next vblank isn't ideal.. we should really be looking
> at the hw FLUSH register value to know if there is still an in-progress
> flush without stalling unnecessarily when there is no pending flush.
> 
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>

Reviewed-by: Sean Paul <sean@xxxxxxxxxx>

> ---
>  .../drm/msm/disp/dpu1/dpu_encoder_phys_vid.c  | 22 ++++++++++++++++++-
>  1 file changed, 21 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> index 737fe963a490..7c73b09894f0 100644
> --- a/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> +++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_encoder_phys_vid.c
> @@ -526,6 +526,26 @@ static int dpu_encoder_phys_vid_wait_for_vblank(
>  	return _dpu_encoder_phys_vid_wait_for_vblank(phys_enc, true);
>  }
>  
> +static int dpu_encoder_phys_vid_wait_for_commit_done(
> +		struct dpu_encoder_phys *phys_enc)
> +{
> +	struct dpu_hw_ctl *hw_ctl = phys_enc->hw_ctl;
> +	int ret;
> +
> +	if (!hw_ctl)
> +		return 0;
> +
> +	ret = wait_event_timeout(phys_enc->pending_kickoff_wq,
> +		(hw_ctl->ops.get_flush_register(hw_ctl) == 0),
> +		msecs_to_jiffies(50));
> +	if (ret <= 0) {
> +		DPU_ERROR("vblank timeout\n");
> +		return -ETIMEDOUT;
> +	}
> +
> +	return 0;
> +}
> +
>  static void dpu_encoder_phys_vid_prepare_for_kickoff(
>  		struct dpu_encoder_phys *phys_enc)
>  {
> @@ -676,7 +696,7 @@ static void dpu_encoder_phys_vid_init_ops(struct dpu_encoder_phys_ops *ops)
>  	ops->destroy = dpu_encoder_phys_vid_destroy;
>  	ops->get_hw_resources = dpu_encoder_phys_vid_get_hw_resources;
>  	ops->control_vblank_irq = dpu_encoder_phys_vid_control_vblank_irq;
> -	ops->wait_for_commit_done = dpu_encoder_phys_vid_wait_for_vblank;
> +	ops->wait_for_commit_done = dpu_encoder_phys_vid_wait_for_commit_done;
>  	ops->wait_for_vblank = dpu_encoder_phys_vid_wait_for_vblank;
>  	ops->wait_for_tx_complete = dpu_encoder_phys_vid_wait_for_vblank;
>  	ops->irq_control = dpu_encoder_phys_vid_irq_control;
> -- 
> 2.21.0
> 

-- 
Sean Paul, Software Engineer, Google / Chromium OS