linux.git/include/drm, branch v6.12.80

drm: of: drm_of_panel_bridge_remove(): fix device_node leak

2026-03-04T12:21:46+00:00

[ Upstream commit a4b4385d0523e39a7c058cb5a6c8269e513126ca ]

drm_of_panel_bridge_remove() uses of_graph_get_remote_node() to get a
device_node but does not put the node reference.

Fixes: c70087e8f16f ("drm/drm_of: add drm_of_panel_bridge_remove function")
Cc: stable@vger.kernel.org # v4.15
Acked-by: Maxime Ripard 
Link: https://patch.msgid.link/20260109-drm-bridge-alloc-getput-drm_of_find_bridge-2-v2-1-8bad3ef90b9f@bootlin.com
Signed-off-by: Luca Ceresoli 
Signed-off-by: Sasha Levin

drm/edid: add DRM_EDID_IDENT_INIT() to initialize struct drm_edid_ident

2026-01-08T09:14:53+00:00

commit 8b61583f993589a64c061aa91b44f5bd350d90a5 upstream.

Add a convenience helper for initializing struct drm_edid_ident.

Cc: Tiago Martins Araújo 
Acked-by: Alex Deucher 
Tested-by: Tiago Martins Araújo 
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/710b2ac6a211606ec1f90afa57b79e8c7375a27e.1761681968.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula 
Signed-off-by: Greg Kroah-Hartman

drm/buddy: Separate clear and dirty free block trees

2026-01-08T09:14:52+00:00

commit d4cd665c98c144dd6ad5d66d30396e13d23118c9 upstream.

Maintain two separate RB trees per order - one for clear (zeroed) blocks
and another for dirty (uncleared) blocks. This separation improves
code clarity and makes it more obvious which tree is being searched
during allocation. It also improves scalability and efficiency when
searching for a specific type of block, avoiding unnecessary checks
and making the allocator more predictable under fragmentation.

The changes have been validated using the existing drm_buddy_test
KUnit test cases, along with selected graphics workloads,
to ensure correctness and avoid regressions.

v2: Missed adding the suggested-by tag. Added it in v2.

v3(Matthew):
  - Remove the double underscores from the internal functions.
  - Rename the internal functions to have less generic names.
  - Fix the error handling code.
  - Pass tree argument for the tree macro.
  - Use the existing dirty/free bit instead of new tree field.
  - Make free_trees[] instead of clear_tree and dirty_tree for
    more cleaner approach.

v4:
  - A bug was reported by Intel CI and it is fixed by
    Matthew Auld.
  - Replace the get_root function with
    &mm->free_trees[tree][order] (Matthew)
  - Remove the unnecessary rbtree_is_empty() check (Matthew)
  - Remove the unnecessary get_tree_for_flags() function.
  - Rename get_tree_for_block() name with get_block_tree() for more
    clarity.

v5(Jani Nikula):
  - Don't use static inline in .c files.
  - enum free_tree and enumerator names are quite generic for a header
    and usage and the whole enum should be an implementation detail.

v6:
  - Rewrite the __force_merge() function using the rb_last() and rb_prev().

v7(Matthew):
  - Replace the open-coded tree iteration for loops with the
    for_each_free_tree() macro throughout the code.
  - Fixed out_free_roots to prevent double decrement of i,
    addressing potential crash.
  - Replaced enum drm_buddy_free_tree with unsigned int
    in for_each_free_tree loops.

Cc: stable@vger.kernel.org
Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
Signed-off-by: Arunpravin Paneer Selvam 
Suggested-by: Matthew Auld 
Reviewed-by: Matthew Auld 
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4260
Link: https://lore.kernel.org/r/20251006095124.1663-2-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Greg Kroah-Hartman

drm/buddy: Optimize free block management with RB tree

2026-01-08T09:14:52+00:00

commit c178e534fff1d5a74da80ea03b20e2b948a00113 upstream.

Replace the freelist (O(n)) used for free block management with a
red-black tree, providing more efficient O(log n) search, insert,
and delete operations. This improves scalability and performance
when managing large numbers of free blocks per order (e.g., hundreds
or thousands).

In the VK-CTS memory stress subtest, the buddy manager merges
fragmented memory and inserts freed blocks into the freelist. Since
freelist insertion is O(n), this becomes a bottleneck as fragmentation
increases. Benchmarking shows list_insert_sorted() consumes ~52.69% CPU
with the freelist, compared to just 0.03% with the RB tree
(rbtree_insert.isra.0), despite performing the same sorted insert.

This also improves performance in heavily fragmented workloads,
such as games or graphics tests that stress memory.

As the buddy allocator evolves with new features such as clear-page
tracking, the resulting fragmentation and complexity have grown.
These RB-tree based design changes are introduced to address that
growth and ensure the allocator continues to perform efficiently
under fragmented conditions.

The RB tree implementation with separate clear/dirty trees provides:
- O(n log n) aggregate complexity for all operations instead of O(n^2)
- Elimination of soft lockups and system instability
- Improved code maintainability and clarity
- Better scalability for large memory systems
- Predictable performance under fragmentation

v3(Matthew):
  - Remove RB_EMPTY_NODE check in force_merge function.
  - Rename rb for loop macros to have less generic names and move to
    .c file.
  - Make the rb node rb and link field as union.

v4(Jani Nikula):
  - The kernel-doc comment should be "/**"
  - Move all the rbtree macros to rbtree.h and add parens to ensure
    correct precedence.

v5:
  - Remove the inline in a .c file (Jani Nikula).

v6(Peter Zijlstra):
  - Add rb_add() function replacing the existing rbtree_insert() code.

v7:
  - A full walk iteration in rbtree is slower than the list (Peter Zijlstra).
  - The existing rbtree_postorder_for_each_entry_safe macro should be used
    in scenarios where traversal order is not a critical factor (Christian).

v8(Matthew):
  - Remove the rbtree_is_empty() check in this patch as well.

Cc: stable@vger.kernel.org
Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
Signed-off-by: Arunpravin Paneer Selvam 
Reviewed-by: Matthew Auld 
Link: https://lore.kernel.org/r/20251006095124.1663-1-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Greg Kroah-Hartman

drm/sched: Re-group and rename the entity run-queue lock

2025-11-13T20:34:01+00:00

[ 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(&entity->rq_lock);
	spin_lock(&entity->rq->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 
Suggested-by: Christian König 
Cc: Alex Deucher 
Cc: Luben Tuikov 
Cc: Matthew Brost 
Cc: Philipp Stanner 
Reviewed-by: Christian König 
[pstanner: Fix typo in docstring]
Signed-off-by: Philipp Stanner 
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 
Signed-off-by: Greg Kroah-Hartman

drm/sched: Optimise drm_sched_entity_push_job

2025-11-13T20:34:01+00:00

[ 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->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 
Cc: Christian König 
Cc: Alex Deucher 
Cc: Luben Tuikov 
Cc: Matthew Brost 
Cc: Philipp Stanner 
Reviewed-by: Christian König 
Signed-off-by: Philipp Stanner 
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 
Signed-off-by: Greg Kroah-Hartman

drm/tests: Do not use drm_fb_blit() in format-helper tests

2025-08-28T14:31:12+00:00

[ 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 
Reviewed-by: José Expósito 
Acked-by: Maxime Ripard 
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

drm/format-helper: Add conversion from XRGB8888 to BGR888

2025-08-28T14:31:11+00:00

[ Upstream commit c9043706cb11b8005e145debe0a3211acd08e2c1 ]

Add XRGB8888 emulation helper for devices that only support BGR888.

Signed-off-by: Kerem Karabay 
Signed-off-by: Aditya Garg 
Reviewed-by: Thomas Zimmermann 
Signed-off-by: Thomas Zimmermann 
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

drm/amdgpu: Reset the clear flag in buddy during resume

2025-08-01T08:48:42+00:00

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 
Suggested-by: Christian König 
Acked-by: Christian König 
Reviewed-by: Matthew Auld 
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 
Link: https://lore.kernel.org/r/20250716075125.240637-2-Arunpravin.PaneerSelvam@amd.com
Signed-off-by: Greg Kroah-Hartman

drm/framebuffer: Acquire internal references on GEM handles

2025-07-17T16:37:12+00:00

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 
Fixes: 5307dce878d4 ("drm/gem: Acquire references on GEM handles for framebuffers")
Reported-by: Bert Karwatzki 
Closes: https://lore.kernel.org/dri-devel/20250703115915.3096-1-spasswolf@web.de/
Tested-by: Bert Karwatzki 
Tested-by: Mario Limonciello 
Tested-by: Borislav Petkov (AMD) 
Cc: Thomas Zimmermann 
Cc: Anusha Srivatsa 
Cc: Christian König 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: Sumit Semwal 
Cc: "Christian König" 
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: 
Reviewed-by: Christian König 
Link: https://lore.kernel.org/r/20250707131224.249496-1-tzimmermann@suse.de
Signed-off-by: Greg Kroah-Hartman