Hi
Am 05.05.25 um 09:29 schrieb Boris Brezillon:
On Wed, 30 Apr 2025 11:07:17 +0200
Simona Vetter <simona.vet...@ffwll.ch> wrote:
On Wed, Apr 16, 2025 at 11:38:03AM +0200, Simona Vetter wrote:
On Wed, Apr 16, 2025 at 08:57:45AM +0200, Thomas Zimmermann wrote:
Test struct drm_gem_object.import_attach to detect imported objects.
During object clenanup, the dma_buf field might be NULL. Testing it in
an object's free callback then incorrectly does a cleanup as for native
objects. Happens for calls to drm_mode_destroy_dumb_ioctl() that
clears the dma_buf field in drm_gem_object_exported_dma_buf_free().
v3:
- only test for import_attach (Boris)
v2:
- use import_attach.dmabuf instead of dma_buf (Christian)
Signed-off-by: Thomas Zimmermann <tzimmerm...@suse.de>
Fixes: b57aa47d39e9 ("drm/gem: Test for imported GEM buffers with helper")
Reported-by: Andy Yan <andys...@163.com>
Closes:
https://lore.kernel.org/dri-devel/38d09d34.4354.196379aa560.coremail.andys...@163.com/
Tested-by: Andy Yan <andys...@163.com>
Cc: Thomas Zimmermann <tzimmerm...@suse.de>
Cc: Anusha Srivatsa <asriv...@redhat.com>
Cc: Christian König <christian.koe...@amd.com>
Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com>
Cc: Maxime Ripard <mrip...@kernel.org>
Cc: David Airlie <airl...@gmail.com>
Cc: Simona Vetter <sim...@ffwll.ch>
Cc: Sumit Semwal <sumit.sem...@linaro.org>
Cc: "Christian König" <christian.koe...@amd.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-me...@vger.kernel.org
Cc: linaro-mm-...@lists.linaro.org
Reviewed-by: Simona Vetter <simona.vet...@ffwll.ch>
Also quick doc request: We do have a bit of overview documentation for
prime here about specifically this lifetime fun, and why there's a chain
of references and hence a distinction between imported foreign dma-buf and
re-imported native dma-buf:
https://dri.freedesktop.org/docs/drm/gpu/drm-mm.html#reference-counting-for-gem-drivers
I think it would be good to augment this with more links to functions
(like this one recently added and fixed in this patch here) and struct
members to that overview. And maybe also link from key function and struct
functions back to that overview doc. Otherwise I think the next person
will get confused by this rather tricky code again and break a corner
cases.
BTW, could we also backmerge 6.15-rc5 into drm-misc-next so the fix is
also present in drm-misc-next?
drm-misc-next is now at -rc5
Best regards
Thomas
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
