Re: [PATCH v2 02/08] drm/amdgpu: screen freeze and userq driver crash

["Christian König" <ckoenig.leichtzumerken@gmail.com>]

Am 25.09.24 um 21:59 schrieb Arunpravin Paneer Selvam:
> Screen freeze and userq fence driver crash while playing Xonotic
>
> v2: (Christian)
>      - There is change that fence might signal in between testing
>        and grabbing the lock. Hence we can move the lock above the
>        if..else check and use the dma_fence_is_signaled_locked().
>
> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> index 96d1caf4c815..97b1af574407 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userq_fence.c
> @@ -185,6 +185,7 @@ int amdgpu_userq_fence_create(struct amdgpu_usermode_queue *userq,
>   	struct amdgpu_userq_fence_driver *fence_drv;
>   	struct amdgpu_userq_fence *userq_fence;
>   	struct dma_fence *fence;
> +	unsigned long flags;
>   
>   	fence_drv = userq->fence_drv;
>   	if (!fence_drv)
> @@ -232,14 +233,14 @@ int amdgpu_userq_fence_create(struct amdgpu_usermode_queue *userq,
>   		userq_fence->fence_drv_array_count = 0;
>   	}
>   
> -	spin_lock(&fence_drv->fence_list_lock);
>   	/* Check if hardware has already processed the job */
> -	if (!dma_fence_is_signaled(fence))
> +	spin_lock_irqsave(&fence_drv->fence_list_lock, flags);
> +	if (!dma_fence_is_signaled_locked(fence))
>   		list_add_tail(&userq_fence->link, &fence_drv->fences);
>   	else
>   		dma_fence_put(fence);
>   
> -	spin_unlock(&fence_drv->fence_list_lock);
> +	spin_unlock_irqrestore(&fence_drv->fence_list_lock, flags);
>   
>   	*f = fence;
>