<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/drm, branch v6.12.61</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>drm/sched: Re-group and rename the entity run-queue lock</title>
<updated>2025-11-13T20:34:01+00:00</updated>
<author>
<name>Tvrtko Ursulin</name>
<email>tvrtko.ursulin@igalia.com</email>
</author>
<published>2025-11-03T12:44:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f78da4cad3b112375881244a3538e2ba0feb2220'/>
<id>f78da4cad3b112375881244a3538e2ba0feb2220</id>
<content type='text'>
[ Upstream commit f93126f5d55920d1447ef00a3fbe6706f40f53de ]

When writing to a drm_sched_entity's run-queue, writers are protected
through the lock drm_sched_entity.rq_lock. This naming, however,
frequently collides with the separate internal lock of struct
drm_sched_rq, resulting in uses like this:

	spin_lock(&amp;entity-&gt;rq_lock);
	spin_lock(&amp;entity-&gt;rq-&gt;lock);

Rename drm_sched_entity.rq_lock to improve readability. While at it,
re-order that struct's members to make it more obvious what the lock
protects.

v2:
 * Rename some rq_lock straddlers in kerneldoc, improve commit text. (Philipp)

Signed-off-by: Tvrtko Ursulin &lt;tvrtko.ursulin@igalia.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Luben Tuikov &lt;ltuikov89@gmail.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Philipp Stanner &lt;pstanner@redhat.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
[pstanner: Fix typo in docstring]
Signed-off-by: Philipp Stanner &lt;pstanner@redhat.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-5-tursulin@igalia.com
Stable-dep-of: d25e3a610bae ("drm/sched: Fix race in drm_sched_entity_select_rq()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f93126f5d55920d1447ef00a3fbe6706f40f53de ]

When writing to a drm_sched_entity's run-queue, writers are protected
through the lock drm_sched_entity.rq_lock. This naming, however,
frequently collides with the separate internal lock of struct
drm_sched_rq, resulting in uses like this:

	spin_lock(&amp;entity-&gt;rq_lock);
	spin_lock(&amp;entity-&gt;rq-&gt;lock);

Rename drm_sched_entity.rq_lock to improve readability. While at it,
re-order that struct's members to make it more obvious what the lock
protects.

v2:
 * Rename some rq_lock straddlers in kerneldoc, improve commit text. (Philipp)

Signed-off-by: Tvrtko Ursulin &lt;tvrtko.ursulin@igalia.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Luben Tuikov &lt;ltuikov89@gmail.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Philipp Stanner &lt;pstanner@redhat.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
[pstanner: Fix typo in docstring]
Signed-off-by: Philipp Stanner &lt;pstanner@redhat.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-5-tursulin@igalia.com
Stable-dep-of: d25e3a610bae ("drm/sched: Fix race in drm_sched_entity_select_rq()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/sched: Optimise drm_sched_entity_push_job</title>
<updated>2025-11-13T20:34:01+00:00</updated>
<author>
<name>Tvrtko Ursulin</name>
<email>tvrtko.ursulin@igalia.com</email>
</author>
<published>2025-11-03T12:44:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=431b4e8c7bfdc7c5535aaa8bf7f1dabf848fca1e'/>
<id>431b4e8c7bfdc7c5535aaa8bf7f1dabf848fca1e</id>
<content type='text'>
[ Upstream commit d42a254633c773921884a19e8a1a0f53a31150c3 ]

In FIFO mode (which is the default), both drm_sched_entity_push_job() and
drm_sched_rq_update_fifo(), where the latter calls the former, are
currently taking and releasing the same entity-&gt;rq_lock.

We can avoid that design inelegance, and also have a miniscule
efficiency improvement on the submit from idle path, by introducing a new
drm_sched_rq_update_fifo_locked() helper and pulling up the lock taking to
its callers.

v2:
 * Remove drm_sched_rq_update_fifo() altogether. (Christian)

v3:
 * Improved commit message. (Philipp)

Signed-off-by: Tvrtko Ursulin &lt;tvrtko.ursulin@igalia.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Luben Tuikov &lt;ltuikov89@gmail.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Philipp Stanner &lt;pstanner@redhat.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Philipp Stanner &lt;pstanner@redhat.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-2-tursulin@igalia.com
Stable-dep-of: d25e3a610bae ("drm/sched: Fix race in drm_sched_entity_select_rq()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d42a254633c773921884a19e8a1a0f53a31150c3 ]

In FIFO mode (which is the default), both drm_sched_entity_push_job() and
drm_sched_rq_update_fifo(), where the latter calls the former, are
currently taking and releasing the same entity-&gt;rq_lock.

We can avoid that design inelegance, and also have a miniscule
efficiency improvement on the submit from idle path, by introducing a new
drm_sched_rq_update_fifo_locked() helper and pulling up the lock taking to
its callers.

v2:
 * Remove drm_sched_rq_update_fifo() altogether. (Christian)

v3:
 * Improved commit message. (Philipp)

Signed-off-by: Tvrtko Ursulin &lt;tvrtko.ursulin@igalia.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Luben Tuikov &lt;ltuikov89@gmail.com&gt;
Cc: Matthew Brost &lt;matthew.brost@intel.com&gt;
Cc: Philipp Stanner &lt;pstanner@redhat.com&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Signed-off-by: Philipp Stanner &lt;pstanner@redhat.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20241016122013.7857-2-tursulin@igalia.com
Stable-dep-of: d25e3a610bae ("drm/sched: Fix race in drm_sched_entity_select_rq()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/tests: Do not use drm_fb_blit() in format-helper tests</title>
<updated>2025-08-28T14:31:12+00:00</updated>
<author>
<name>Thomas Zimmermann</name>
<email>tzimmermann@suse.de</email>
</author>
<published>2025-06-16T08:37:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=46d9ebf9fd825b70edb6ca7e590e3fda7f0e8d63'/>
<id>46d9ebf9fd825b70edb6ca7e590e3fda7f0e8d63</id>
<content type='text'>
[ Upstream commit 5a4856e0e38109ba994f369962f054ecb445c098 ]

Export additional helpers from the format-helper library and open-code
drm_fb_blit() in tests. Prepares for the removal of drm_fb_blit(). Only
sysfb drivers use drm_fb_blit(). The function will soon be removed from
format helpers and be refactored within sysfb helpers.

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Reviewed-by: José Expósito &lt;jose.exposito89@gmail.com&gt;
Acked-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Link: https://lore.kernel.org/r/20250616083846.221396-2-tzimmermann@suse.de
Stable-dep-of: 05663d88fd0b ("drm/tests: Fix drm_test_fb_xrgb8888_to_xrgb2101010() on big-endian")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 5a4856e0e38109ba994f369962f054ecb445c098 ]

Export additional helpers from the format-helper library and open-code
drm_fb_blit() in tests. Prepares for the removal of drm_fb_blit(). Only
sysfb drivers use drm_fb_blit(). The function will soon be removed from
format helpers and be refactored within sysfb helpers.

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Reviewed-by: José Expósito &lt;jose.exposito89@gmail.com&gt;
Acked-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Link: https://lore.kernel.org/r/20250616083846.221396-2-tzimmermann@suse.de
Stable-dep-of: 05663d88fd0b ("drm/tests: Fix drm_test_fb_xrgb8888_to_xrgb2101010() on big-endian")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/format-helper: Add conversion from XRGB8888 to BGR888</title>
<updated>2025-08-28T14:31:11+00:00</updated>
<author>
<name>Kerem Karabay</name>
<email>kekrby@gmail.com</email>
</author>
<published>2025-02-26T16:03:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=d218e87db084a952fbc8c487b75af399880e1228'/>
<id>d218e87db084a952fbc8c487b75af399880e1228</id>
<content type='text'>
[ Upstream commit c9043706cb11b8005e145debe0a3211acd08e2c1 ]

Add XRGB8888 emulation helper for devices that only support BGR888.

Signed-off-by: Kerem Karabay &lt;kekrby@gmail.com&gt;
Signed-off-by: Aditya Garg &lt;gargaditya08@live.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/9A67EA95-9BC7-4D56-8F87-05EAC1C166AD@live.com
Stable-dep-of: 05663d88fd0b ("drm/tests: Fix drm_test_fb_xrgb8888_to_xrgb2101010() on big-endian")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c9043706cb11b8005e145debe0a3211acd08e2c1 ]

Add XRGB8888 emulation helper for devices that only support BGR888.

Signed-off-by: Kerem Karabay &lt;kekrby@gmail.com&gt;
Signed-off-by: Aditya Garg &lt;gargaditya08@live.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/9A67EA95-9BC7-4D56-8F87-05EAC1C166AD@live.com
Stable-dep-of: 05663d88fd0b ("drm/tests: Fix drm_test_fb_xrgb8888_to_xrgb2101010() on big-endian")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/amdgpu: Reset the clear flag in buddy during resume</title>
<updated>2025-08-01T08:48:42+00:00</updated>
<author>
<name>Arunpravin Paneer Selvam</name>
<email>Arunpravin.PaneerSelvam@amd.com</email>
</author>
<published>2025-07-16T07:51:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=198604687f19737e6149f7b8667ddf1177f079e0'/>
<id>198604687f19737e6149f7b8667ddf1177f079e0</id>
<content type='text'>
commit 95a16160ca1d75c66bf7a1c5e0bcaffb18e7c7fc upstream.

- Added a handler in DRM buddy manager to reset the cleared
  flag for the blocks in the freelist.

- This is necessary because, upon resuming, the VRAM becomes
  cluttered with BIOS data, yet the VRAM backend manager
  believes that everything has been cleared.

v2:
  - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
  - Force merge the two dirty blocks.(Matthew Auld)
  - Add a new unit test case for this issue.(Matthew Auld)
  - Having this function being able to flip the state either way would be
    good. (Matthew Brost)

v3(Matthew Auld):
  - Do merge step first to avoid the use of extra reset flag.

Signed-off-by: Arunpravin Paneer Selvam &lt;Arunpravin.PaneerSelvam@amd.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Reviewed-by: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: stable@vger.kernel.org
Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Link: https://lore.kernel.org/r/20250716075125.240637-2-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 95a16160ca1d75c66bf7a1c5e0bcaffb18e7c7fc upstream.

- Added a handler in DRM buddy manager to reset the cleared
  flag for the blocks in the freelist.

- This is necessary because, upon resuming, the VRAM becomes
  cluttered with BIOS data, yet the VRAM backend manager
  believes that everything has been cleared.

v2:
  - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
  - Force merge the two dirty blocks.(Matthew Auld)
  - Add a new unit test case for this issue.(Matthew Auld)
  - Having this function being able to flip the state either way would be
    good. (Matthew Brost)

v3(Matthew Auld):
  - Do merge step first to avoid the use of extra reset flag.

Signed-off-by: Arunpravin Paneer Selvam &lt;Arunpravin.PaneerSelvam@amd.com&gt;
Suggested-by: Christian König &lt;christian.koenig@amd.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Reviewed-by: Matthew Auld &lt;matthew.auld@intel.com&gt;
Cc: stable@vger.kernel.org
Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Link: https://lore.kernel.org/r/20250716075125.240637-2-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/framebuffer: Acquire internal references on GEM handles</title>
<updated>2025-07-17T16:37:12+00:00</updated>
<author>
<name>Thomas Zimmermann</name>
<email>tzimmermann@suse.de</email>
</author>
<published>2025-07-07T13:11:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=065bd940ee0a0033ea9a7dbb1a9110baef9415a4'/>
<id>065bd940ee0a0033ea9a7dbb1a9110baef9415a4</id>
<content type='text'>
commit f6bfc9afc7510cb5e6fbe0a17c507917b0120280 upstream.

Acquire GEM handles in drm_framebuffer_init() and release them in
the corresponding drm_framebuffer_cleanup(). Ties the handle's
lifetime to the framebuffer. Not all GEM buffer objects have GEM
handles. If not set, no refcounting takes place. This is the case
for some fbdev emulation. This is not a problem as these GEM objects
do not use dma-bufs and drivers will not release them while fbdev
emulation is running. Framebuffer flags keep a bit per color plane
of which the framebuffer holds a GEM handle reference.

As all drivers use drm_framebuffer_init(), they will now all hold
dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire
references on GEM handles for framebuffers").

In the GEM framebuffer helpers, restore the original ref counting
on buffer objects. As the helpers for handle refcounting are now
no longer called from outside the DRM core, unexport the symbols.

v3:
- don't mix internal flags with mode flags (Christian)
v2:
- track framebuffer handle refs by flag
- drop gma500 cleanup (Christian)

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers")
Reported-by: Bert Karwatzki &lt;spasswolf@web.de&gt;
Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/
Tested-by: Bert Karwatzki &lt;spasswolf@web.de&gt;
Tested-by: Mario Limonciello &lt;superm1@kernel.org&gt;
Tested-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: Anusha Srivatsa &lt;asrivats@redhat.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Cc: "Christian König" &lt;christian.koenig@amd.com&gt;
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f6bfc9afc7510cb5e6fbe0a17c507917b0120280 upstream.

Acquire GEM handles in drm_framebuffer_init() and release them in
the corresponding drm_framebuffer_cleanup(). Ties the handle's
lifetime to the framebuffer. Not all GEM buffer objects have GEM
handles. If not set, no refcounting takes place. This is the case
for some fbdev emulation. This is not a problem as these GEM objects
do not use dma-bufs and drivers will not release them while fbdev
emulation is running. Framebuffer flags keep a bit per color plane
of which the framebuffer holds a GEM handle reference.

As all drivers use drm_framebuffer_init(), they will now all hold
dma-buf references as fixed in commit 5307dce878d4 ("drm/gem: Acquire
references on GEM handles for framebuffers").

In the GEM framebuffer helpers, restore the original ref counting
on buffer objects. As the helpers for handle refcounting are now
no longer called from outside the DRM core, unexport the symbols.

v3:
- don't mix internal flags with mode flags (Christian)
v2:
- track framebuffer handle refs by flag
- drop gma500 cleanup (Christian)

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers")
Reported-by: Bert Karwatzki &lt;spasswolf@web.de&gt;
Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/
Tested-by: Bert Karwatzki &lt;spasswolf@web.de&gt;
Tested-by: Mario Limonciello &lt;superm1@kernel.org&gt;
Tested-by: Borislav Petkov (AMD) &lt;bp@alien8.de&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: Anusha Srivatsa &lt;asrivats@redhat.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Cc: "Christian König" &lt;christian.koenig@amd.com&gt;
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Christian König &lt;christian.koenig@amd.com&gt;
Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/gem: Fix race in drm_gem_handle_create_tail()</title>
<updated>2025-07-17T16:37:11+00:00</updated>
<author>
<name>Simona Vetter</name>
<email>simona.vetter@ffwll.ch</email>
</author>
<published>2025-07-07T15:18:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=2d2f07a9948756acdcd8aed14b4596482f51ac0f'/>
<id>2d2f07a9948756acdcd8aed14b4596482f51ac0f</id>
<content type='text'>
commit bd46cece51a36ef088f22ef0416ac13b0a46d5b0 upstream.

Object creation is a careful dance where we must guarantee that the
object is fully constructed before it is visible to other threads, and
GEM buffer objects are no difference.

Final publishing happens by calling drm_gem_handle_create(). After
that the only allowed thing to do is call drm_gem_object_put() because
a concurrent call to the GEM_CLOSE ioctl with a correctly guessed id
(which is trivial since we have a linear allocator) can already tear
down the object again.

Luckily most drivers get this right, the very few exceptions I've
pinged the relevant maintainers for. Unfortunately we also need
drm_gem_handle_create() when creating additional handles for an
already existing object (e.g. GETFB ioctl or the various bo import
ioctl), and hence we cannot have a drm_gem_handle_create_and_put() as
the only exported function to stop these issues from happening.

Now unfortunately the implementation of drm_gem_handle_create() isn't
living up to standards: It does correctly finishe object
initialization at the global level, and hence is safe against a
concurrent tear down. But it also sets up the file-private aspects of
the handle, and that part goes wrong: We fully register the object in
the drm_file.object_idr before calling drm_vma_node_allow() or
obj-&gt;funcs-&gt;open, which opens up races against concurrent removal of
that handle in drm_gem_handle_delete().

Fix this with the usual two-stage approach of first reserving the
handle id, and then only registering the object after we've completed
the file-private setup.

Jacek reported this with a testcase of concurrently calling GEM_CLOSE
on a freshly-created object (which also destroys the object), but it
should be possible to hit this with just additional handles created
through import or GETFB without completed destroying the underlying
object with the concurrent GEM_CLOSE ioctl calls.

Note that the close-side of this race was fixed in f6cd7daecff5 ("drm:
Release driver references to handle before making it available
again"), which means a cool 9 years have passed until someone noticed
that we need to make this symmetry or there's still gaps left :-/
Without the 2-stage close approach we'd still have a race, therefore
that's an integral part of this bugfix.

More importantly, this means we can have NULL pointers behind
allocated id in our drm_file.object_idr. We need to check for that
now:

- drm_gem_handle_delete() checks for ERR_OR_NULL already

- drm_gem.c:object_lookup() also chekcs for NULL

- drm_gem_release() should never be called if there's another thread
  still existing that could call into an IOCTL that creates a new
  handle, so cannot race. For paranoia I added a NULL check to
  drm_gem_object_release_handle() though.

- most drivers (etnaviv, i915, msm) are find because they use
  idr_find(), which maps both ENOENT and NULL to NULL.

- drivers using idr_for_each_entry() should also be fine, because
  idr_get_next does filter out NULL entries and continues the
  iteration.

- The same holds for drm_show_memory_stats().

v2: Use drm_WARN_ON (Thomas)

Reported-by: Jacek Lawrynowicz &lt;jacek.lawrynowicz@linux.intel.com&gt;
Tested-by: Jacek Lawrynowicz &lt;jacek.lawrynowicz@linux.intel.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: stable@vger.kernel.org
Cc: Jacek Lawrynowicz &lt;jacek.lawrynowicz@linux.intel.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@intel.com&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250707151814.603897-1-simona.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bd46cece51a36ef088f22ef0416ac13b0a46d5b0 upstream.

Object creation is a careful dance where we must guarantee that the
object is fully constructed before it is visible to other threads, and
GEM buffer objects are no difference.

Final publishing happens by calling drm_gem_handle_create(). After
that the only allowed thing to do is call drm_gem_object_put() because
a concurrent call to the GEM_CLOSE ioctl with a correctly guessed id
(which is trivial since we have a linear allocator) can already tear
down the object again.

Luckily most drivers get this right, the very few exceptions I've
pinged the relevant maintainers for. Unfortunately we also need
drm_gem_handle_create() when creating additional handles for an
already existing object (e.g. GETFB ioctl or the various bo import
ioctl), and hence we cannot have a drm_gem_handle_create_and_put() as
the only exported function to stop these issues from happening.

Now unfortunately the implementation of drm_gem_handle_create() isn't
living up to standards: It does correctly finishe object
initialization at the global level, and hence is safe against a
concurrent tear down. But it also sets up the file-private aspects of
the handle, and that part goes wrong: We fully register the object in
the drm_file.object_idr before calling drm_vma_node_allow() or
obj-&gt;funcs-&gt;open, which opens up races against concurrent removal of
that handle in drm_gem_handle_delete().

Fix this with the usual two-stage approach of first reserving the
handle id, and then only registering the object after we've completed
the file-private setup.

Jacek reported this with a testcase of concurrently calling GEM_CLOSE
on a freshly-created object (which also destroys the object), but it
should be possible to hit this with just additional handles created
through import or GETFB without completed destroying the underlying
object with the concurrent GEM_CLOSE ioctl calls.

Note that the close-side of this race was fixed in f6cd7daecff5 ("drm:
Release driver references to handle before making it available
again"), which means a cool 9 years have passed until someone noticed
that we need to make this symmetry or there's still gaps left :-/
Without the 2-stage close approach we'd still have a race, therefore
that's an integral part of this bugfix.

More importantly, this means we can have NULL pointers behind
allocated id in our drm_file.object_idr. We need to check for that
now:

- drm_gem_handle_delete() checks for ERR_OR_NULL already

- drm_gem.c:object_lookup() also chekcs for NULL

- drm_gem_release() should never be called if there's another thread
  still existing that could call into an IOCTL that creates a new
  handle, so cannot race. For paranoia I added a NULL check to
  drm_gem_object_release_handle() though.

- most drivers (etnaviv, i915, msm) are find because they use
  idr_find(), which maps both ENOENT and NULL to NULL.

- drivers using idr_for_each_entry() should also be fine, because
  idr_get_next does filter out NULL entries and continues the
  iteration.

- The same holds for drm_show_memory_stats().

v2: Use drm_WARN_ON (Thomas)

Reported-by: Jacek Lawrynowicz &lt;jacek.lawrynowicz@linux.intel.com&gt;
Tested-by: Jacek Lawrynowicz &lt;jacek.lawrynowicz@linux.intel.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: stable@vger.kernel.org
Cc: Jacek Lawrynowicz &lt;jacek.lawrynowicz@linux.intel.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@intel.com&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250707151814.603897-1-simona.vetter@ffwll.ch
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/sched: Increment job count before swapping tail spsc queue</title>
<updated>2025-07-17T16:37:11+00:00</updated>
<author>
<name>Matthew Brost</name>
<email>matthew.brost@intel.com</email>
</author>
<published>2025-06-13T21:20:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=e2d6547dc8b9b332f9bc00875197287a6a4db65a'/>
<id>e2d6547dc8b9b332f9bc00875197287a6a4db65a</id>
<content type='text'>
commit 8af39ec5cf2be522c8eb43a3d8005ed59e4daaee upstream.

A small race exists between spsc_queue_push and the run-job worker, in
which spsc_queue_push may return not-first while the run-job worker has
already idled due to the job count being zero. If this race occurs, job
scheduling stops, leading to hangs while waiting on the job’s DMA
fences.

Seal this race by incrementing the job count before appending to the
SPSC queue.

This race was observed on a drm-tip 6.16-rc1 build with the Xe driver in
an SVM test case.

Fixes: 1b1f42d8fde4 ("drm: move amd_gpu_scheduler into common location")
Fixes: 27105db6c63a ("drm/amdgpu: Add SPSC queue to scheduler.")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Brost &lt;matthew.brost@intel.com&gt;
Reviewed-by: Jonathan Cavitt &lt;jonathan.cavitt@intel.com&gt;
Link: https://lore.kernel.org/r/20250613212013.719312-1-matthew.brost@intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8af39ec5cf2be522c8eb43a3d8005ed59e4daaee upstream.

A small race exists between spsc_queue_push and the run-job worker, in
which spsc_queue_push may return not-first while the run-job worker has
already idled due to the job count being zero. If this race occurs, job
scheduling stops, leading to hangs while waiting on the job’s DMA
fences.

Seal this race by incrementing the job count before appending to the
SPSC queue.

This race was observed on a drm-tip 6.16-rc1 build with the Xe driver in
an SVM test case.

Fixes: 1b1f42d8fde4 ("drm: move amd_gpu_scheduler into common location")
Fixes: 27105db6c63a ("drm/amdgpu: Add SPSC queue to scheduler.")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Brost &lt;matthew.brost@intel.com&gt;
Reviewed-by: Jonathan Cavitt &lt;jonathan.cavitt@intel.com&gt;
Link: https://lore.kernel.org/r/20250613212013.719312-1-matthew.brost@intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/gem: Internally test import_attach for imported objects</title>
<updated>2025-05-29T09:03:26+00:00</updated>
<author>
<name>Thomas Zimmermann</name>
<email>tzimmermann@suse.de</email>
</author>
<published>2025-04-16T06:57:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=85fb1edd059bf7ac3070ec98b64486fc54da3b65'/>
<id>85fb1edd059bf7ac3070ec98b64486fc54da3b65</id>
<content type='text'>
commit 8260731ccad0451207b45844bb66eb161a209218 upstream.

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 &lt;tzimmermann@suse.de&gt;
Fixes: b57aa47d39e9 ("drm/gem: Test for imported GEM buffers with helper")
Reported-by: Andy Yan &lt;andyshrk@163.com&gt;
Closes: https://lore.kernel.org/dri-devel/38d09d34.4354.196379aa560.Coremail.andyshrk@163.com/
Tested-by: Andy Yan &lt;andyshrk@163.com&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: Anusha Srivatsa &lt;asrivats@redhat.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Cc: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Cc: "Christian König" &lt;christian.koenig@amd.com&gt;
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Reviewed-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://lore.kernel.org/r/20250416065820.26076-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8260731ccad0451207b45844bb66eb161a209218 upstream.

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 &lt;tzimmermann@suse.de&gt;
Fixes: b57aa47d39e9 ("drm/gem: Test for imported GEM buffers with helper")
Reported-by: Andy Yan &lt;andyshrk@163.com&gt;
Closes: https://lore.kernel.org/dri-devel/38d09d34.4354.196379aa560.Coremail.andyshrk@163.com/
Tested-by: Andy Yan &lt;andyshrk@163.com&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: Anusha Srivatsa &lt;asrivats@redhat.com&gt;
Cc: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Simona Vetter &lt;simona@ffwll.ch&gt;
Cc: Sumit Semwal &lt;sumit.semwal@linaro.org&gt;
Cc: "Christian König" &lt;christian.koenig@amd.com&gt;
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Boris Brezillon &lt;boris.brezillon@collabora.com&gt;
Reviewed-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://lore.kernel.org/r/20250416065820.26076-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/atomic: clarify the rules around drm_atomic_state-&gt;allow_modeset</title>
<updated>2025-05-29T09:03:09+00:00</updated>
<author>
<name>Simona Vetter</name>
<email>simona.vetter@ffwll.ch</email>
</author>
<published>2025-01-08T17:24:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=135105287781eb6693f0075c63c0b3e6d68f7e62'/>
<id>135105287781eb6693f0075c63c0b3e6d68f7e62</id>
<content type='text'>
[ Upstream commit c5e3306a424b52e38ad2c28c7f3399fcd03e383d ]

msm is automagically upgrading normal commits to full modesets, and
that's a big no-no:

- for one this results in full on-&gt;off-&gt;on transitions on all these
  crtc, at least if you're using the usual helpers. Which seems to be
  the case, and is breaking uapi

- further even if the ctm change itself would not result in flicker,
  this can hide modesets for other reasons. Which again breaks the
  uapi

v2: I forgot the case of adding unrelated crtc state. Add that case
and link to the existing kerneldoc explainers. This has come up in an
irc discussion with Manasi and Ville about intel's bigjoiner mode.
Also cc everyone involved in the msm irc discussion, more people
joined after I sent out v1.

v3: Wording polish from Pekka and Thomas

Acked-by: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Acked-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Cc: Rob Clark &lt;robdclark@gmail.com&gt;
Cc: Simon Ser &lt;contact@emersion.fr&gt;
Cc: Manasi Navare &lt;navaremanasi@google.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Cc: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@intel.com&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250108172417.160831-1-simona.vetter@ffwll.ch
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit c5e3306a424b52e38ad2c28c7f3399fcd03e383d ]

msm is automagically upgrading normal commits to full modesets, and
that's a big no-no:

- for one this results in full on-&gt;off-&gt;on transitions on all these
  crtc, at least if you're using the usual helpers. Which seems to be
  the case, and is breaking uapi

- further even if the ctm change itself would not result in flicker,
  this can hide modesets for other reasons. Which again breaks the
  uapi

v2: I forgot the case of adding unrelated crtc state. Add that case
and link to the existing kerneldoc explainers. This has come up in an
irc discussion with Manasi and Ville about intel's bigjoiner mode.
Also cc everyone involved in the msm irc discussion, more people
joined after I sent out v1.

v3: Wording polish from Pekka and Thomas

Acked-by: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Acked-by: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Cc: Maarten Lankhorst &lt;maarten.lankhorst@linux.intel.com&gt;
Cc: Maxime Ripard &lt;mripard@kernel.org&gt;
Cc: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Cc: David Airlie &lt;airlied@gmail.com&gt;
Cc: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Cc: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Cc: Rob Clark &lt;robdclark@gmail.com&gt;
Cc: Simon Ser &lt;contact@emersion.fr&gt;
Cc: Manasi Navare &lt;navaremanasi@google.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Abhinav Kumar &lt;quic_abhinavk@quicinc.com&gt;
Cc: Dmitry Baryshkov &lt;dmitry.baryshkov@linaro.org&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@intel.com&gt;
Signed-off-by: Simona Vetter &lt;simona.vetter@ffwll.ch&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20250108172417.160831-1-simona.vetter@ffwll.ch
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
