Commit c9402efe authored by Christian König's avatar Christian König Committed by Christian König
Browse files

dma-buf: add a warning when drv try to reserve 0 fence slots 



When dma_resv_reserve_fences() is called with num_fences=0 it usually
means that a driver or other component messed up its calculation how
many fences are needed. Warn in that situation.

When no fence are needed the function shouldn't be called in the first
place.

Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240529084322.2284-1-christian.koenig@amd.com


Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
parent c4e32678

drivers/dma-buf/dma-resv.c

+7 −0
Original line number Diff line number Diff line
@@ -186,6 +186,13 @@ int dma_resv_reserve_fences(struct dma_resv *obj, unsigned int num_fences) 


	dma_resv_assert_held(obj);



	/* Driver and component code should never call this function with

	 * num_fences=0. If they do it usually points to bugs when calculating

	 * the number of needed fences dynamically.

	 */

	if (WARN_ON(!num_fences))

		return -EINVAL;



	old = dma_resv_fences_list(obj);

	if (old && old->max_fences) {

		if ((old->num_fences + num_fences) <= old->max_fences)