Re: [PATCH 1/8] drm/panfrost: Make panfrost_job_run() return an ERR_PTR() instead of NULL

[Steven Price <steven.price@arm.com>]

On 29/11/2019 13:59, Boris Brezillon wrote:
> If we don't do that, dma_fence_set_error() complains (called from
> drm_sched_main()).
> 
> Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver")
> Cc: <stable@vger.kernel.org>
> Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>

This might be worth doing, but actually it's not Panfrost that is broken
it's the callers, see [1] and [2]. So I don't think we want the
Fixes/stable tag.

[1] https://patchwork.kernel.org/patch/11218399/
[2] https://patchwork.kernel.org/patch/11267073/

> ---
>  drivers/gpu/drm/panfrost/panfrost_job.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
> index 21f34d44aac2..cdd9448fbbdd 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_job.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_job.c
> @@ -328,13 +328,13 @@ static struct dma_fence *panfrost_job_run(struct drm_sched_job *sched_job)
>  	struct dma_fence *fence = NULL;
>  
>  	if (unlikely(job->base.s_fence->finished.error))
> -		return NULL;
> +		return ERR_PTR(job->base.s_fence->finished.error);
>  
>  	pfdev->jobs[slot] = job;
>  
>  	fence = panfrost_fence_create(pfdev, slot);
>  	if (IS_ERR(fence))
> -		return NULL;
> +		return ERR_PTR(-ENOMEM);

Why override the error from panfrost_fence_create? In this case we can just:

	return fence;

Steve

>  
>  	if (job->done_fence)
>  		dma_fence_put(job->done_fence);
>