[Intel-xe] [PATCH 4/6] drm/xe/bo: Gracefully handle errors from ttm_bo_move_accel_cleanup().

[Matthew Brost]

On Fri, Jun 16, 2023 at 11:55:02AM +0200, Thomas Hellström wrote:
> The function ttm_bo_move_accel_cleanup() attempts to help pipeline a
> move, and in doing so, needs memory allocations which may fail.
> 
> Rather than failing in a state where the new resource may freed while
> accessed by the copy engine, sync uninterruptible and do a failsafe
> cleanup.
> 
> Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
> ---
>  drivers/gpu/drm/xe/xe_bo.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 94dd11066f51..77d5c5710688 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -689,10 +689,15 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
>  		if (!move_lacks_source) {
>  			ret = ttm_bo_move_accel_cleanup(ttm_bo, fence, evict,
>  							true, new_mem);
> -		} else {
> +			if (ret)
> +				dma_fence_wait(fence, false);

Should it be:
	if (ret == -ENOMEM)
		dma_fence_wait(fence, false);

> +		}
> +
> +		if (move_lacks_source || ret) {
Should it be:
		if (move_lacks_source || ret == -ENOMEM) {

Matt

>  			dma_resv_add_fence(ttm_bo->base.resv, fence,
>  					   DMA_RESV_USAGE_KERNEL);
>  			ttm_bo_move_null(ttm_bo, new_mem);
> +			ret = 0;
>  		}
>  
>  		dma_fence_put(fence);
> -- 
> 2.40.1
>