Re: [PATCH] drm/xe: Use dma_fence_chain_free in chain fence unused as a sync

[Matthew Auld <matthew.auld@intel.com>]

On 27/07/2024 02:22, Matthew Brost wrote:
> A chain fence is uninitialized if not installed in a drm sync obj. Thus
> if xe_sync_entry_cleanup is called and sync->chain_fence is non-NULL the
> proper cleanup is dma_fence_chain_free rather than a dma-fence put.
> 
> Reported-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2411
> Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs")
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>

Reviewed-by: Matthew Auld <matthew.auld@intel.com>

Also maybe:
https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2261

> ---
>   drivers/gpu/drm/xe/xe_sync.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_sync.c b/drivers/gpu/drm/xe/xe_sync.c
> index 533246f42256..3aa6270e5dd7 100644
> --- a/drivers/gpu/drm/xe/xe_sync.c
> +++ b/drivers/gpu/drm/xe/xe_sync.c
> @@ -259,7 +259,7 @@ void xe_sync_entry_cleanup(struct xe_sync_entry *sync)
>   	if (sync->fence)
>   		dma_fence_put(sync->fence);
>   	if (sync->chain_fence)
> -		dma_fence_put(&sync->chain_fence->base);
> +		dma_fence_chain_free(sync->chain_fence);
>   	if (sync->ufence)
>   		user_fence_put(sync->ufence);
>   }