<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/drm, branch v6.6.31</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>mm, treewide: introduce NR_PAGE_ORDERS</title>
<updated>2024-05-02T14:32:41+00:00</updated>
<author>
<name>Kirill A. Shutemov</name>
<email>kirill.shutemov@linux.intel.com</email>
</author>
<published>2023-12-28T14:47:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ded1ffea52132e58eaaa7d4ea39477f911796a40'/>
<id>ded1ffea52132e58eaaa7d4ea39477f911796a40</id>
<content type='text'>
[ Upstream commit fd37721803c6e73619108f76ad2e12a9aa5fafaf ]

NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.

NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.

[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
  Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Stable-dep-of: b6976f323a86 ("drm/ttm: stop pooling cached NUMA pages v2")
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 fd37721803c6e73619108f76ad2e12a9aa5fafaf ]

NR_PAGE_ORDERS defines the number of page orders supported by the page
allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total.

NR_PAGE_ORDERS assists in defining arrays of page orders and allows for
more natural iteration over them.

[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
  Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov &lt;kirill.shutemov@linux.intel.com&gt;
Reviewed-by: Zi Yan &lt;ziy@nvidia.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Stable-dep-of: b6976f323a86 ("drm/ttm: stop pooling cached NUMA pages v2")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: add drm_gem_object_is_shared_for_memory_stats() helper</title>
<updated>2024-05-02T14:32:41+00:00</updated>
<author>
<name>Alex Deucher</name>
<email>alexander.deucher@amd.com</email>
</author>
<published>2024-02-12T21:04:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a4ae24cd04a8e2c1f61586a2e129b1cbd44a78db'/>
<id>a4ae24cd04a8e2c1f61586a2e129b1cbd44a78db</id>
<content type='text'>
[ Upstream commit b31f5eba32ae8cc28e7cfa5a55ec8670d8c718e2 ]

Add a helper so that drm drivers can consistently report
shared status via the fdinfo shared memory stats interface.

In addition to handle count, show buffers as shared if they
are shared via dma-buf as well (e.g., shared with v4l or some
other subsystem).

v2: switch to inline function

Link: https://lore.kernel.org/all/20231207180225.439482-1-alexander.deucher@amd.com/
Reviewed-by: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt; (v1)
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Reviewed-by: Christian König &lt;christian.keonig@amd.com&gt;
Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Stable-dep-of: a6ff969fe9cb ("drm/amdgpu: fix visible VRAM handling during faults")
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 b31f5eba32ae8cc28e7cfa5a55ec8670d8c718e2 ]

Add a helper so that drm drivers can consistently report
shared status via the fdinfo shared memory stats interface.

In addition to handle count, show buffers as shared if they
are shared via dma-buf as well (e.g., shared with v4l or some
other subsystem).

v2: switch to inline function

Link: https://lore.kernel.org/all/20231207180225.439482-1-alexander.deucher@amd.com/
Reviewed-by: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt; (v1)
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Reviewed-by: Christian König &lt;christian.keonig@amd.com&gt;
Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Stable-dep-of: a6ff969fe9cb ("drm/amdgpu: fix visible VRAM handling during faults")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/bridge: add -&gt;edid_read hook and drm_bridge_edid_read()</title>
<updated>2024-04-03T13:28:38+00:00</updated>
<author>
<name>Jani Nikula</name>
<email>jani.nikula@intel.com</email>
</author>
<published>2024-01-23T19:37:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2b6aaf7b193be2bfa4e1af90c0d96e78a80aef69'/>
<id>2b6aaf7b193be2bfa4e1af90c0d96e78a80aef69</id>
<content type='text'>
[ Upstream commit d807ad80d811ba0c22adfd871e2a46491f80d6e2 ]

Add new struct drm_edid based -&gt;edid_read hook and
drm_bridge_edid_read() function to call the hook.

v2: Include drm/drm_edid.h

Signed-off-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Reviewed-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/9d08d22eaffcb9c59a2b677e45d7e61fc689bc2f.1706038510.git.jani.nikula@intel.com
Stable-dep-of: 171b711b26cc ("drm/bridge: lt8912b: do not return negative values from .get_modes()")
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 d807ad80d811ba0c22adfd871e2a46491f80d6e2 ]

Add new struct drm_edid based -&gt;edid_read hook and
drm_bridge_edid_read() function to call the hook.

v2: Include drm/drm_edid.h

Signed-off-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Reviewed-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/9d08d22eaffcb9c59a2b677e45d7e61fc689bc2f.1706038510.git.jani.nikula@intel.com
Stable-dep-of: 171b711b26cc ("drm/bridge: lt8912b: do not return negative values from .get_modes()")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/ttm: Make sure the mapped tt pages are decrypted when needed</title>
<updated>2024-04-03T13:28:38+00:00</updated>
<author>
<name>Zack Rusin</name>
<email>zack.rusin@broadcom.com</email>
</author>
<published>2024-01-05T13:51:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=de125efb3bae7720d10364a9ab6785466e4e2461'/>
<id>de125efb3bae7720d10364a9ab6785466e4e2461</id>
<content type='text'>
[ Upstream commit 71ce046327cfd3aef3f93d1c44e091395eb03f8f ]

Some drivers require the mapped tt pages to be decrypted. In an ideal
world this would have been handled by the dma layer, but the TTM page
fault handling would have to be rewritten to able to do that.

A side-effect of the TTM page fault handling is using a dma allocation
per order (via ttm_pool_alloc_page) which makes it impossible to just
trivially use dma_mmap_attrs. As a result ttm has to be very careful
about trying to make its pgprot for the mapped tt pages match what
the dma layer thinks it is. At the ttm layer it's possible to
deduce the requirement to have tt pages decrypted by checking
whether coherent dma allocations have been requested and the system
is running with confidential computing technologies.

This approach isn't ideal but keeping TTM matching DMAs expectations
for the page properties is in general fragile, unfortunately proper
fix would require a rewrite of TTM's page fault handling.

Fixes vmwgfx with SEV enabled.

v2: Explicitly include cc_platform.h
v3: Use CC_ATTR_GUEST_MEM_ENCRYPT instead of CC_ATTR_MEM_ENCRYPT to
limit the scope to guests and log when memory decryption is enabled.

Signed-off-by: Zack Rusin &lt;zack.rusin@broadcom.com&gt;
Fixes: 3bf3710e3718 ("drm/ttm: Add a generic TTM memcpy move for page-based iomem")
Reviewed-by: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Huang Rui &lt;ray.huang@amd.com&gt;
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc: &lt;stable@vger.kernel.org&gt; # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20230926040359.3040017-1-zack@kde.org
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 71ce046327cfd3aef3f93d1c44e091395eb03f8f ]

Some drivers require the mapped tt pages to be decrypted. In an ideal
world this would have been handled by the dma layer, but the TTM page
fault handling would have to be rewritten to able to do that.

A side-effect of the TTM page fault handling is using a dma allocation
per order (via ttm_pool_alloc_page) which makes it impossible to just
trivially use dma_mmap_attrs. As a result ttm has to be very careful
about trying to make its pgprot for the mapped tt pages match what
the dma layer thinks it is. At the ttm layer it's possible to
deduce the requirement to have tt pages decrypted by checking
whether coherent dma allocations have been requested and the system
is running with confidential computing technologies.

This approach isn't ideal but keeping TTM matching DMAs expectations
for the page properties is in general fragile, unfortunately proper
fix would require a rewrite of TTM's page fault handling.

Fixes vmwgfx with SEV enabled.

v2: Explicitly include cc_platform.h
v3: Use CC_ATTR_GUEST_MEM_ENCRYPT instead of CC_ATTR_MEM_ENCRYPT to
limit the scope to guests and log when memory decryption is enabled.

Signed-off-by: Zack Rusin &lt;zack.rusin@broadcom.com&gt;
Fixes: 3bf3710e3718 ("drm/ttm: Add a generic TTM memcpy move for page-based iomem")
Reviewed-by: Thomas Hellström &lt;thomas.hellstrom@linux.intel.com&gt;
Acked-by: Christian König &lt;christian.koenig@amd.com&gt;
Cc: Huang Rui &lt;ray.huang@amd.com&gt;
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Cc: &lt;stable@vger.kernel.org&gt; # v5.14+
Link: https://patchwork.freedesktop.org/patch/msgid/20230926040359.3040017-1-zack@kde.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/probe-helper: warn about negative .get_modes()</title>
<updated>2024-04-03T13:28:32+00:00</updated>
<author>
<name>Jani Nikula</name>
<email>jani.nikula@intel.com</email>
</author>
<published>2024-03-08T16:03:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=12bbe2c25cdb571190d523fd814e7696964a84d9'/>
<id>12bbe2c25cdb571190d523fd814e7696964a84d9</id>
<content type='text'>
[ Upstream commit 7af03e688792293ba33149fb8df619a8dff90e80 ]

The .get_modes() callback is supposed to return the number of modes,
never a negative error code. If a negative value is returned, it'll just
be interpreted as a negative count, and added to previous calculations.

Document the rules, but handle the negative values gracefully with an
error message.

Cc: stable@vger.kernel.org
Acked-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/50208c866facc33226a3c77b82bb96aeef8ef310.1709913674.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
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 7af03e688792293ba33149fb8df619a8dff90e80 ]

The .get_modes() callback is supposed to return the number of modes,
never a negative error code. If a negative value is returned, it'll just
be interpreted as a negative count, and added to previous calculations.

Document the rules, but handle the negative values gracefully with an
error message.

Cc: stable@vger.kernel.org
Acked-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/50208c866facc33226a3c77b82bb96aeef8ef310.1709913674.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: Fix drm_fixp2int_round() making it add 0.5</title>
<updated>2024-03-26T22:20:10+00:00</updated>
<author>
<name>Arthur Grillo</name>
<email>arthurgrillo@riseup.net</email>
</author>
<published>2024-03-16T16:25:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=296e6678a432aaff0b8c6a6a17b9b2b193556c71'/>
<id>296e6678a432aaff0b8c6a6a17b9b2b193556c71</id>
<content type='text'>
[ Upstream commit 807f96abdf14c80f534c78f2d854c2590963345c ]

As well noted by Pekka[1], the rounding of drm_fixp2int_round is wrong.
To round a number, you need to add 0.5 to the number and floor that,
drm_fixp2int_round() is adding 0.0000076. Make it add 0.5.

[1]: https://lore.kernel.org/all/20240301135327.22efe0dd.pekka.paalanen@collabora.com/

Fixes: 8b25320887d7 ("drm: Add fixed-point helper to get rounded integer values")
Suggested-by: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Reviewed-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Reviewed-by: Melissa Wen &lt;mwen@igalia.com&gt;
Signed-off-by: Arthur Grillo &lt;arthurgrillo@riseup.net&gt;
Signed-off-by: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240316-drm_fixed-v2-1-c1bc2665b5ed@riseup.net
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 807f96abdf14c80f534c78f2d854c2590963345c ]

As well noted by Pekka[1], the rounding of drm_fixp2int_round is wrong.
To round a number, you need to add 0.5 to the number and floor that,
drm_fixp2int_round() is adding 0.0000076. Make it add 0.5.

[1]: https://lore.kernel.org/all/20240301135327.22efe0dd.pekka.paalanen@collabora.com/

Fixes: 8b25320887d7 ("drm: Add fixed-point helper to get rounded integer values")
Suggested-by: Pekka Paalanen &lt;pekka.paalanen@collabora.com&gt;
Reviewed-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Reviewed-by: Melissa Wen &lt;mwen@igalia.com&gt;
Signed-off-by: Arthur Grillo &lt;arthurgrillo@riseup.net&gt;
Signed-off-by: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240316-drm_fixed-v2-1-c1bc2665b5ed@riseup.net
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/tests: helpers: Include missing drm_drv header</title>
<updated>2024-03-26T22:19:53+00:00</updated>
<author>
<name>Maxime Ripard</name>
<email>mripard@kernel.org</email>
</author>
<published>2024-02-22T18:13:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f14cbcd0b5c9bb198753baad8d9243393fe7554'/>
<id>4f14cbcd0b5c9bb198753baad8d9243393fe7554</id>
<content type='text'>
[ Upstream commit 73984daf07a1a89ace8f0db6dd2d640654ebbbee ]

We have a few functions declared in our kunit helpers header, some of
them dereferencing the struct drm_driver.

However, we don't include the drm_drv.h header file defining that
structure, leading to compilation errors if we don't include both
headers.

Fixes: d98780310719 ("drm/tests: helpers: Allow to pass a custom drm_driver")
Reviewed-by: Maíra Canal &lt;mcanal@igalia.com&gt;
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-1-8f4af575fce2@kernel.org
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 73984daf07a1a89ace8f0db6dd2d640654ebbbee ]

We have a few functions declared in our kunit helpers header, some of
them dereferencing the struct drm_driver.

However, we don't include the drm_drv.h header file defining that
structure, leading to compilation errors if we don't include both
headers.

Fixes: d98780310719 ("drm/tests: helpers: Allow to pass a custom drm_driver")
Reviewed-by: Maíra Canal &lt;mcanal@igalia.com&gt;
Signed-off-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20240222-kms-hdmi-connector-state-v7-1-8f4af575fce2@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: Don't treat 0 as -1 in drm_fixp2int_ceil</title>
<updated>2024-03-26T22:19:42+00:00</updated>
<author>
<name>Harry Wentland</name>
<email>harry.wentland@amd.com</email>
</author>
<published>2023-11-08T16:36:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bac3d37d2f7cab3d9c42a7c9775c84aee4fa89d9'/>
<id>bac3d37d2f7cab3d9c42a7c9775c84aee4fa89d9</id>
<content type='text'>
[ Upstream commit cf8837d7204481026335461629b84ac7f4538fa5 ]

Unit testing this in VKMS shows that passing 0 into
this function returns -1, which is highly counter-
intuitive. Fix it by checking whether the input is
&gt;= 0 instead of &gt; 0.

Fixes: 64566b5e767f ("drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil")
Signed-off-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Reviewed-by: Simon Ser &lt;contact@emersion.fr&gt;
Reviewed-by: Melissa Wen &lt;mwen@igalia.com&gt;
Signed-off-by: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20231108163647.106853-2-harry.wentland@amd.com
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 cf8837d7204481026335461629b84ac7f4538fa5 ]

Unit testing this in VKMS shows that passing 0 into
this function returns -1, which is highly counter-
intuitive. Fix it by checking whether the input is
&gt;= 0 instead of &gt; 0.

Fixes: 64566b5e767f ("drm: Add drm_fixp_from_fraction and drm_fixp2int_ceil")
Signed-off-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Reviewed-by: Simon Ser &lt;contact@emersion.fr&gt;
Reviewed-by: Melissa Wen &lt;mwen@igalia.com&gt;
Signed-off-by: Melissa Wen &lt;melissa.srw@gmail.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20231108163647.106853-2-harry.wentland@amd.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm: using mul_u32_u32() requires linux/math64.h</title>
<updated>2024-02-05T20:14:34+00:00</updated>
<author>
<name>Stephen Rothwell</name>
<email>sfr@canb.auug.org.au</email>
</author>
<published>2023-12-19T03:57:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8de8f000ffe1c930d0cdf73cfce91b0d1746c3bc'/>
<id>8de8f000ffe1c930d0cdf73cfce91b0d1746c3bc</id>
<content type='text'>
[ Upstream commit 933a2a376fb3f22ba4774f74233571504ac56b02 ]

Some pending include file cleanups produced this error:

In file included from include/linux/kernel.h:27,
                 from drivers/gpu/ipu-v3/ipu-dp.c:7:
include/drm/drm_color_mgmt.h: In function 'drm_color_lut_extract':
include/drm/drm_color_mgmt.h:45:46: error: implicit declaration of function 'mul_u32_u32' [-Werror=implicit-function-declaration]
   45 |                 return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 &lt;&lt; bit_precision) - 1),
      |                                              ^~~~~~~~~~~

Fixes: c6fbb6bca108 ("drm: Fix color LUT rounding")
Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20231219145734.13e40e1e@canb.auug.org.au
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 933a2a376fb3f22ba4774f74233571504ac56b02 ]

Some pending include file cleanups produced this error:

In file included from include/linux/kernel.h:27,
                 from drivers/gpu/ipu-v3/ipu-dp.c:7:
include/drm/drm_color_mgmt.h: In function 'drm_color_lut_extract':
include/drm/drm_color_mgmt.h:45:46: error: implicit declaration of function 'mul_u32_u32' [-Werror=implicit-function-declaration]
   45 |                 return DIV_ROUND_CLOSEST_ULL(mul_u32_u32(user_input, (1 &lt;&lt; bit_precision) - 1),
      |                                              ^~~~~~~~~~~

Fixes: c6fbb6bca108 ("drm: Fix color LUT rounding")
Signed-off-by: Stephen Rothwell &lt;sfr@canb.auug.org.au&gt;
Signed-off-by: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20231219145734.13e40e1e@canb.auug.org.au
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mipi-dsi: Fix detach call without attach</title>
<updated>2024-02-05T20:14:27+00:00</updated>
<author>
<name>Tomi Valkeinen</name>
<email>tomi.valkeinen@ideasonboard.com</email>
</author>
<published>2023-09-21T10:50:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=daf57c5ce16e907405d8a59a4f2be20e204906e4'/>
<id>daf57c5ce16e907405d8a59a4f2be20e204906e4</id>
<content type='text'>
[ Upstream commit 90d50b8d85834e73536fdccd5aa913b30494fef0 ]

It's been reported that DSI host driver's detach can be called without
the attach ever happening:

https://lore.kernel.org/all/20230412073954.20601-1-tony@atomide.com/

After reading the code, I think this is what happens:

We have a DSI host defined in the device tree and a DSI peripheral under
that host (i.e. an i2c device using the DSI as data bus doesn't exhibit
this behavior).

The host driver calls mipi_dsi_host_register(), which causes (via a few
functions) mipi_dsi_device_add() to be called for the DSI peripheral. So
now we have a DSI device under the host, but attach hasn't been called.

Normally the probing of the devices continues, and eventually the DSI
peripheral's driver will call mipi_dsi_attach(), attaching the
peripheral.

However, if the host driver's probe encounters an error after calling
mipi_dsi_host_register(), and before the peripheral has called
mipi_dsi_attach(), the host driver will do cleanups and return an error
from its probe function. The cleanups include calling
mipi_dsi_host_unregister().

mipi_dsi_host_unregister() will call two functions for all its DSI
peripheral devices: mipi_dsi_detach() and mipi_dsi_device_unregister().
The latter makes sense, as the device exists, but the former may be
wrong as attach has not necessarily been done.

To fix this, track the attached state of the peripheral, and only detach
from mipi_dsi_host_unregister() if the peripheral was attached.

Note that I have only tested this with a board with an i2c DSI
peripheral, not with a "pure" DSI peripheral.

However, slightly related, the unregister machinery still seems broken.
E.g. if the DSI host driver is unbound, it'll detach and unregister the
DSI peripherals. After that, when the DSI peripheral driver unbound
it'll call detach either directly or using the devm variant, leading to
a crash. And probably the driver will crash if it happens, for some
reason, to try to send a message via the DSI bus.

But that's another topic.

Tested-by: H. Nikolaus Schaller &lt;hns@goldelico.com&gt;
Acked-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Reviewed-by: Sebastian Reichel &lt;sebastian.reichel@collabora.com&gt;
Tested-by: Tony Lindgren &lt;tony@atomide.com&gt;
Signed-off-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230921-dsi-detach-fix-v1-1-d0de2d1621d9@ideasonboard.com
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 90d50b8d85834e73536fdccd5aa913b30494fef0 ]

It's been reported that DSI host driver's detach can be called without
the attach ever happening:

https://lore.kernel.org/all/20230412073954.20601-1-tony@atomide.com/

After reading the code, I think this is what happens:

We have a DSI host defined in the device tree and a DSI peripheral under
that host (i.e. an i2c device using the DSI as data bus doesn't exhibit
this behavior).

The host driver calls mipi_dsi_host_register(), which causes (via a few
functions) mipi_dsi_device_add() to be called for the DSI peripheral. So
now we have a DSI device under the host, but attach hasn't been called.

Normally the probing of the devices continues, and eventually the DSI
peripheral's driver will call mipi_dsi_attach(), attaching the
peripheral.

However, if the host driver's probe encounters an error after calling
mipi_dsi_host_register(), and before the peripheral has called
mipi_dsi_attach(), the host driver will do cleanups and return an error
from its probe function. The cleanups include calling
mipi_dsi_host_unregister().

mipi_dsi_host_unregister() will call two functions for all its DSI
peripheral devices: mipi_dsi_detach() and mipi_dsi_device_unregister().
The latter makes sense, as the device exists, but the former may be
wrong as attach has not necessarily been done.

To fix this, track the attached state of the peripheral, and only detach
from mipi_dsi_host_unregister() if the peripheral was attached.

Note that I have only tested this with a board with an i2c DSI
peripheral, not with a "pure" DSI peripheral.

However, slightly related, the unregister machinery still seems broken.
E.g. if the DSI host driver is unbound, it'll detach and unregister the
DSI peripherals. After that, when the DSI peripheral driver unbound
it'll call detach either directly or using the devm variant, leading to
a crash. And probably the driver will crash if it happens, for some
reason, to try to send a message via the DSI bus.

But that's another topic.

Tested-by: H. Nikolaus Schaller &lt;hns@goldelico.com&gt;
Acked-by: Maxime Ripard &lt;mripard@kernel.org&gt;
Reviewed-by: Sebastian Reichel &lt;sebastian.reichel@collabora.com&gt;
Tested-by: Tony Lindgren &lt;tony@atomide.com&gt;
Signed-off-by: Tomi Valkeinen &lt;tomi.valkeinen@ideasonboard.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230921-dsi-detach-fix-v1-1-d0de2d1621d9@ideasonboard.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
