Commit 7106bf96 authored Aug 15, 2013 by Daniel Vetter Committed by Dave Airlie Aug 19, 2013

drm/prime: add a bit of documentation about gem_obj->import_attach



Lifetime rules seem to be solid around ->import_attach. So this patch
just properly documents them.

Note that pointing directly at the attachment might have issues for
devices that have multiple struct device *dev parts constituting the
logical gpu and so might need multiple attachment points. Similarly
for drm devices which don't need a dma attachment at all (like udl).

But fixing that up is material for different patches.

Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

parent 01ce605a

include/drm/drmP.h

+10 −1

Original line number	Diff line number	Diff line
		@@ -665,7 +665,16 @@ struct drm_gem_object {
		/* dma buf exported from this GEM object */
		struct dma_buf *export_dma_buf;

		/* dma buf attachment backing this object */
		/**
		* import_attach - dma buf attachment backing this object
		*
		* Any foreign dma_buf imported as a gem object has this set to the
		* attachment point for the device. This is invariant over the lifetime
		* of a gem object.
		*
		* The driver's ->gem_free_object callback is responsible for cleaning
		* up the dma_buf attachment and references acquired at import time.
		*/
		struct dma_buf_attachment *import_attach;
		};