diff options
| author |   Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-12-11 16:58:43 +0100 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2020-12-16 11:28:34 +0100 |
| commit | c545781e1c55ab680dcc49c37212d5327b9d6812 (patch) | |
| tree | 14152db8d82354f45b4ff3e89270bc4b4010734e /include/linux/dma-buf.h | |
| parent | dma-buf: begin/end_cpu might lock the dma_resv lock (diff) | |
| download | linux-dev-c545781e1c55ab680dcc49c37212d5327b9d6812.tar.xz linux-dev-c545781e1c55ab680dcc49c37212d5327b9d6812.zip | |
dma-buf: doc polish for pin/unpin
Motivated by a discussion with Christian and Thomas: Try to untangle a
bit what's relevant for importers and what's relevant for exporters.
Also add an assert that really only dynamic importers use the api
function, anything else doesn't make sense.
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Daniel 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/20201211155843.3348718-4-daniel.vetter@ffwll.ch
Diffstat (limited to 'include/linux/dma-buf.h')
| -rw-r--r-- | include/linux/dma-buf.h | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h index 43802a31b25d..628681bf6c99 100644 --- a/include/linux/dma-buf.h +++ b/include/linux/dma-buf.h @@ -86,13 +86,15 @@ struct dma_buf_ops { * @pin: * * This is called by dma_buf_pin() and lets the exporter know that the - * DMA-buf can't be moved any more. + * DMA-buf can't be moved any more. The exporter should pin the buffer + * into system memory to make sure it is generally accessible by other + * devices. * * This is called with the &dmabuf.resv object locked and is mutual * exclusive with @cache_sgt_mapping. * - * This callback is optional and should only be used in limited use - * cases like scanout and not for temporary pin operations. + * This is called automatically for non-dynamic importers from + * dma_buf_attach(). * * Returns: * |