Re: [PATCH v1 2/2] drm: Clear the fence pointer when writeback job signaled

[Brian Starkey <Brian.Starkey@arm.com>]

Hi Lowry,

Thanks for this cleanup.

On Wed, Jul 31, 2019 at 11:04:45AM +0000, Lowry Li (Arm Technology China) wrote:
> During it signals the completion of a writeback job, after releasing
> the out_fence, we'd clear the pointer.
> 
> Check if fence left over in drm_writeback_cleanup_job(), release it.
> 
> Signed-off-by: Lowry Li (Arm Technology China) <lowry.li@arm.com>
> ---
>  drivers/gpu/drm/drm_writeback.c | 23 +++++++++++++++--------
>  1 file changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_writeback.c b/drivers/gpu/drm/drm_writeback.c
> index ff138b6..43d9e3b 100644
> --- a/drivers/gpu/drm/drm_writeback.c
> +++ b/drivers/gpu/drm/drm_writeback.c
> @@ -324,6 +324,9 @@ void drm_writeback_cleanup_job(struct drm_writeback_job *job)
>  	if (job->fb)
>  		drm_framebuffer_put(job->fb);
>  
> +	if (job->out_fence)

I'm thinking it might be a good idea to signal the fence with an error
here, if it's not already signaled. Otherwise, if there's someone
waiting (which there shouldn't be), they're going to be waiting a very
long time :-)

Thanks,
-Brian

> +		dma_fence_put(job->out_fence);
> +
>  	kfree(job);
>  }