From: Daniel Vetter Date: Mon, 14 Dec 2020 17:16:22 +0000 (+0100) Subject: dma-buf: begin/end_cpu might lock the dma_resv lock X-Git-Tag: v5.15~303^2~28^2~1058 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8ccf0a29af75326fb8e5ed6e51ff61e74b7ed2e4;p=platform%2Fkernel%2Flinux-starfive.git 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: Christian König Signed-off-by: Daniel Vetter Cc: Thomas Zimmermann Cc: Sumit Semwal Cc: "Christian König" 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 --- diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c index e1fa6c6..a0a02ef 100644 --- a/drivers/dma-buf/dma-buf.c +++ b/drivers/dma-buf/dma-buf.c @@ -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);