Commit 8ccf0a29 authored by Daniel Vetter's avatar Daniel Vetter
Browse files

dma-buf: begin/end_cpu might lock the dma_resv lock 



At least amdgpu and i915 do, so lets just document this as the rule.

v2: Works better with less typos (intel-gfx-ci)

Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@intel.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Link: https://patchwork.freedesktop.org/patch/msgid/20201214171622.3868883-1-daniel.vetter@ffwll.ch
parent 85804b70

drivers/dma-buf/dma-buf.c

+4 −0
Original line number Diff line number Diff line
@@ -1118,6 +1118,8 @@ int dma_buf_begin_cpu_access(struct dma_buf *dmabuf, 
	if (WARN_ON(!dmabuf))

		return -EINVAL;



	might_lock(&dmabuf->resv->lock.base);



	if (dmabuf->ops->begin_cpu_access)

		ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
@@ -1151,6 +1153,8 @@ int dma_buf_end_cpu_access(struct dma_buf *dmabuf, 


	WARN_ON(!dmabuf);



	might_lock(&dmabuf->resv->lock.base);



	if (dmabuf->ops->end_cpu_access)

		ret = dmabuf->ops->end_cpu_access(dmabuf, direction);