<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/drm, branch v6.2.8</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>drm/bridge: Fix returned array size name for atomic_get_input_bus_fmts kdoc</title>
<updated>2023-03-22T12:37:49+00:00</updated>
<author>
<name>Liu Ying</name>
<email>victor.liu@nxp.com</email>
</author>
<published>2023-03-14T05:50:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b9aa889895177283eb9173a1bcb2f7d2e16b4215'/>
<id>b9aa889895177283eb9173a1bcb2f7d2e16b4215</id>
<content type='text'>
[ Upstream commit 0d3c9333d976af41d7dbc6bf4d9d2e95fbdf9c89 ]

The returned array size for input formats is set through
atomic_get_input_bus_fmts()'s 'num_input_fmts' argument, so use
'num_input_fmts' to represent the array size in the function's kdoc,
not 'num_output_fmts'.

Fixes: 91ea83306bfa ("drm/bridge: Fix the bridge kernel doc")
Fixes: f32df58acc68 ("drm/bridge: Add the necessary bits to support bus format negotiation")
Signed-off-by: Liu Ying &lt;victor.liu@nxp.com&gt;
Reviewed-by: Robert Foss &lt;rfoss@kernel.org&gt;
Signed-off-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230314055035.3731179-1-victor.liu@nxp.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 0d3c9333d976af41d7dbc6bf4d9d2e95fbdf9c89 ]

The returned array size for input formats is set through
atomic_get_input_bus_fmts()'s 'num_input_fmts' argument, so use
'num_input_fmts' to represent the array size in the function's kdoc,
not 'num_output_fmts'.

Fixes: 91ea83306bfa ("drm/bridge: Fix the bridge kernel doc")
Fixes: f32df58acc68 ("drm/bridge: Add the necessary bits to support bus format negotiation")
Signed-off-by: Liu Ying &lt;victor.liu@nxp.com&gt;
Reviewed-by: Robert Foss &lt;rfoss@kernel.org&gt;
Signed-off-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230314055035.3731179-1-victor.liu@nxp.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/msm/gem: Prevent blocking within shrinker loop</title>
<updated>2023-03-22T12:37:40+00:00</updated>
<author>
<name>Dmitry Osipenko</name>
<email>dmitry.osipenko@collabora.com</email>
</author>
<published>2022-11-04T16:04:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3d824c7df54d5818eaaddf9a6ebbed794058bdf8'/>
<id>3d824c7df54d5818eaaddf9a6ebbed794058bdf8</id>
<content type='text'>
[ Upstream commit 9630b585b607bd26f505d34620b14d75b9a5af7d ]

Consider this scenario:

1. APP1 continuously creates lots of small GEMs
2. APP2 triggers `drop_caches`
3. Shrinker starts to evict APP1 GEMs, while APP1 produces new purgeable
   GEMs
4. msm_gem_shrinker_scan() returns non-zero number of freed pages
   and causes shrinker to try shrink more
5. msm_gem_shrinker_scan() returns non-zero number of freed pages again,
   goto 4
6. The APP2 is blocked in `drop_caches` until APP1 stops producing
   purgeable GEMs

To prevent this blocking scenario, check number of remaining pages
that GPU shrinker couldn't release due to a GEM locking contention
or shrinking rejection. If there are no remaining pages left to shrink,
then there is no need to free up more pages and shrinker may break out
from the loop.

This problem was found during shrinker/madvise IOCTL testing of
virtio-gpu driver. The MSM driver is affected in the same way.

Reviewed-by: Rob Clark &lt;robdclark@gmail.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Fixes: b352ba54a820 ("drm/msm/gem: Convert to using drm_gem_lru")
Signed-off-by: Dmitry Osipenko &lt;dmitry.osipenko@collabora.com&gt;
Link: https://lore.kernel.org/all/20230108210445.3948344-2-dmitry.osipenko@collabora.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 9630b585b607bd26f505d34620b14d75b9a5af7d ]

Consider this scenario:

1. APP1 continuously creates lots of small GEMs
2. APP2 triggers `drop_caches`
3. Shrinker starts to evict APP1 GEMs, while APP1 produces new purgeable
   GEMs
4. msm_gem_shrinker_scan() returns non-zero number of freed pages
   and causes shrinker to try shrink more
5. msm_gem_shrinker_scan() returns non-zero number of freed pages again,
   goto 4
6. The APP2 is blocked in `drop_caches` until APP1 stops producing
   purgeable GEMs

To prevent this blocking scenario, check number of remaining pages
that GPU shrinker couldn't release due to a GEM locking contention
or shrinking rejection. If there are no remaining pages left to shrink,
then there is no need to free up more pages and shrinker may break out
from the loop.

This problem was found during shrinker/madvise IOCTL testing of
virtio-gpu driver. The MSM driver is affected in the same way.

Reviewed-by: Rob Clark &lt;robdclark@gmail.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Fixes: b352ba54a820 ("drm/msm/gem: Convert to using drm_gem_lru")
Signed-off-by: Dmitry Osipenko &lt;dmitry.osipenko@collabora.com&gt;
Link: https://lore.kernel.org/all/20230108210445.3948344-2-dmitry.osipenko@collabora.com/
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/display/dp_mst: Handle old/new payload states in drm_dp_remove_payload()</title>
<updated>2023-03-11T12:50:49+00:00</updated>
<author>
<name>Imre Deak</name>
<email>imre.deak@intel.com</email>
</author>
<published>2023-02-06T11:48:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b2909a3dff6b21448c806c92dcf5852cb6c6c516'/>
<id>b2909a3dff6b21448c806c92dcf5852cb6c6c516</id>
<content type='text'>
commit e761cc20946a0094df71cb31a565a6a0d03bd8be upstream.

Atm, drm_dp_remove_payload() uses the same payload state to both get the
vc_start_slot required for the payload removal DPCD message and to
deduct time_slots from vc_start_slot of all payloads after the one being
removed.

The above isn't always correct, as vc_start_slot must be the up-to-date
version contained in the new payload state, but time_slots must be the
one used when the payload was previously added, contained in the old
payload state. The new payload's time_slots can change vs. the old one
if the current atomic commit changes the corresponding mode.

This patch let's drivers pass the old and new payload states to
drm_dp_remove_payload(), but keeps these the same for now in all drivers
not to change the behavior. A follow-up i915 patch will pass in that
driver the correct old and new states to the function.

Cc: Lyude Paul &lt;lyude@redhat.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Cc: Karol Herbst &lt;kherbst@redhat.com&gt;
Cc: Harry Wentland &lt;harry.wentland@amd.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Wayne Lin &lt;Wayne.Lin@amd.com&gt;
Cc: stable@vger.kernel.org # 6.1
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Reviewed-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Acked-by: Wayne Lin &lt;wayne.lin@amd.com&gt;
Acked-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Signed-off-by: Imre Deak &lt;imre.deak@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230206114856.2665066-2-imre.deak@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 e761cc20946a0094df71cb31a565a6a0d03bd8be upstream.

Atm, drm_dp_remove_payload() uses the same payload state to both get the
vc_start_slot required for the payload removal DPCD message and to
deduct time_slots from vc_start_slot of all payloads after the one being
removed.

The above isn't always correct, as vc_start_slot must be the up-to-date
version contained in the new payload state, but time_slots must be the
one used when the payload was previously added, contained in the old
payload state. The new payload's time_slots can change vs. the old one
if the current atomic commit changes the corresponding mode.

This patch let's drivers pass the old and new payload states to
drm_dp_remove_payload(), but keeps these the same for now in all drivers
not to change the behavior. A follow-up i915 patch will pass in that
driver the correct old and new states to the function.

Cc: Lyude Paul &lt;lyude@redhat.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: Ben Skeggs &lt;bskeggs@redhat.com&gt;
Cc: Karol Herbst &lt;kherbst@redhat.com&gt;
Cc: Harry Wentland &lt;harry.wentland@amd.com&gt;
Cc: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Cc: Wayne Lin &lt;Wayne.Lin@amd.com&gt;
Cc: stable@vger.kernel.org # 6.1
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Reviewed-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Acked-by: Wayne Lin &lt;wayne.lin@amd.com&gt;
Acked-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Signed-off-by: Imre Deak &lt;imre.deak@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230206114856.2665066-2-imre.deak@intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/display/dp_mst: Add drm_atomic_get_old_mst_topology_state()</title>
<updated>2023-03-11T12:50:48+00:00</updated>
<author>
<name>Imre Deak</name>
<email>imre.deak@intel.com</email>
</author>
<published>2023-02-06T11:48:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf9215c5dd5491be60139fb8eff474e456250298'/>
<id>bf9215c5dd5491be60139fb8eff474e456250298</id>
<content type='text'>
commit 9ffdb67af0ee625ae127711845532f670cc6a4e7 upstream.

Add a function to get the old MST topology state, required by a
follow-up i915 patch.

While at it clarify the code comment of
drm_atomic_get_new_mst_topology_state() and add _new prefix
to the new state pointer to remind about its difference from the old
state.

v2: Use old_/new_ prefixes for the state pointers. (Ville)

Cc: Lyude Paul &lt;lyude@redhat.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: stable@vger.kernel.org # 6.1
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Reviewed-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Acked-by: Wayne Lin &lt;wayne.lin@amd.com&gt;
Acked-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Signed-off-by: Imre Deak &lt;imre.deak@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230206114856.2665066-3-imre.deak@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 9ffdb67af0ee625ae127711845532f670cc6a4e7 upstream.

Add a function to get the old MST topology state, required by a
follow-up i915 patch.

While at it clarify the code comment of
drm_atomic_get_new_mst_topology_state() and add _new prefix
to the new state pointer to remind about its difference from the old
state.

v2: Use old_/new_ prefixes for the state pointers. (Ville)

Cc: Lyude Paul &lt;lyude@redhat.com&gt;
Cc: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Cc: stable@vger.kernel.org # 6.1
Cc: dri-devel@lists.freedesktop.org
Reviewed-by: Ville Syrjälä &lt;ville.syrjala@linux.intel.com&gt;
Reviewed-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Lyude Paul &lt;lyude@redhat.com&gt;
Acked-by: Daniel Vetter &lt;daniel@ffwll.ch&gt;
Acked-by: Wayne Lin &lt;wayne.lin@amd.com&gt;
Acked-by: Jani Nikula &lt;jani.nikula@intel.com&gt;
Signed-off-by: Imre Deak &lt;imre.deak@intel.com&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230206114856.2665066-3-imre.deak@intel.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/drm_print: correct format problem</title>
<updated>2023-03-10T08:29:17+00:00</updated>
<author>
<name>Wayne Lin</name>
<email>Wayne.Lin@amd.com</email>
</author>
<published>2022-12-23T01:57:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d099b0f127c1c1a05db320bc1d67be5ca4edd60d'/>
<id>d099b0f127c1c1a05db320bc1d67be5ca4edd60d</id>
<content type='text'>
[ Upstream commit d987150b539271b0394f24c1c648d2846662adb4 ]

[why &amp; how]
__drm_dbg() parameter set format is wrong and not aligned with the
format under CONFIG_DRM_USE_DYNAMIC_DEBUG is on. Fix it.

Signed-off-by: Wayne Lin &lt;Wayne.Lin@amd.com&gt;
Signed-off-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Acked-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Reviewed-by: Lyude Paul &lt;lyude@redhat.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.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 d987150b539271b0394f24c1c648d2846662adb4 ]

[why &amp; how]
__drm_dbg() parameter set format is wrong and not aligned with the
format under CONFIG_DRM_USE_DYNAMIC_DEBUG is on. Fix it.

Signed-off-by: Wayne Lin &lt;Wayne.Lin@amd.com&gt;
Signed-off-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Acked-by: Harry Wentland &lt;harry.wentland@amd.com&gt;
Reviewed-by: Lyude Paul &lt;lyude@redhat.com&gt;
Signed-off-by: Alex Deucher &lt;alexander.deucher@amd.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/mipi-dsi: Fix byte order of 16-bit DCS set/get brightness</title>
<updated>2023-03-10T08:28:31+00:00</updated>
<author>
<name>Daniel Mentz</name>
<email>danielmentz@google.com</email>
</author>
<published>2023-01-16T22:49:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e819faf4a8446c030c503fecfe47f713cd59f19c'/>
<id>e819faf4a8446c030c503fecfe47f713cd59f19c</id>
<content type='text'>
[ Upstream commit c9d27c6be518b4ef2966d9564654ef99292ea1b3 ]

The MIPI DCS specification demands that brightness values are sent in
big endian byte order. It also states that one parameter (i.e. one byte)
shall be sent/received for 8 bit wide values, and two parameters shall
be used for values that are between 9 and 16 bits wide.

Add new functions to properly handle 16-bit brightness in big endian,
since the two 8- and 16-bit cases are distinct from each other.

[richard: use separate functions instead of switch/case]
[richard: split into 16-bit component]

Fixes: 1a9d759331b8 ("drm/dsi: Implement DCS set/get display brightness")
Signed-off-by: Daniel Mentz &lt;danielmentz@google.com&gt;
Link: https://android.googlesource.com/kernel/msm/+/754affd62d0ee268c686c53169b1dbb7deac8550
[richard: fix 16-bit brightness_get]
Signed-off-by: Richard Acayan &lt;mailingradian@gmail.com&gt;
Tested-by: Caleb Connolly &lt;caleb@connolly.tech&gt;
Reviewed-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Reviewed-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230116224909.23884-2-mailingradian@gmail.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 c9d27c6be518b4ef2966d9564654ef99292ea1b3 ]

The MIPI DCS specification demands that brightness values are sent in
big endian byte order. It also states that one parameter (i.e. one byte)
shall be sent/received for 8 bit wide values, and two parameters shall
be used for values that are between 9 and 16 bits wide.

Add new functions to properly handle 16-bit brightness in big endian,
since the two 8- and 16-bit cases are distinct from each other.

[richard: use separate functions instead of switch/case]
[richard: split into 16-bit component]

Fixes: 1a9d759331b8 ("drm/dsi: Implement DCS set/get display brightness")
Signed-off-by: Daniel Mentz &lt;danielmentz@google.com&gt;
Link: https://android.googlesource.com/kernel/msm/+/754affd62d0ee268c686c53169b1dbb7deac8550
[richard: fix 16-bit brightness_get]
Signed-off-by: Richard Acayan &lt;mailingradian@gmail.com&gt;
Tested-by: Caleb Connolly &lt;caleb@connolly.tech&gt;
Reviewed-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Reviewed-by: Sam Ravnborg &lt;sam@ravnborg.org&gt;
Signed-off-by: Neil Armstrong &lt;neil.armstrong@linaro.org&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230116224909.23884-2-mailingradian@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/client: fix circular reference counting issue</title>
<updated>2023-02-07T08:42:56+00:00</updated>
<author>
<name>Christian König</name>
<email>christian.koenig@amd.com</email>
</author>
<published>2023-01-26T09:24:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=85e26dd5100a182bf8448050427539c0a66ab793'/>
<id>85e26dd5100a182bf8448050427539c0a66ab793</id>
<content type='text'>
We reference dump buffers both by their handle as well as their
object. The problem is now that when anybody iterates over the DRM
framebuffers and exports the underlying GEM objects through DMA-buf
we run into a circular reference count situation.

The result is that the fbdev handling holds the GEM handle preventing
the DMA-buf in the GEM object to be released. This DMA-buf in turn
holds a reference to the driver module which on unload would release
the fbdev.

Break that loop by releasing the handle as soon as the DRM
framebuffer object is created. The DRM framebuffer and the DRM client
buffer structure still hold a reference to the underlying GEM object
preventing its destruction.

Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Fixes: c76f0f7cb546 ("drm: Begin an API for in-kernel clients")
Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Tested-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230126102814.8722-1-christian.koenig@amd.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We reference dump buffers both by their handle as well as their
object. The problem is now that when anybody iterates over the DRM
framebuffers and exports the underlying GEM objects through DMA-buf
we run into a circular reference count situation.

The result is that the fbdev handling holds the GEM handle preventing
the DMA-buf in the GEM object to be released. This DMA-buf in turn
holds a reference to the driver module which on unload would release
the fbdev.

Break that loop by releasing the handle as soon as the DRM
framebuffer object is created. The DRM framebuffer and the DRM client
buffer structure still hold a reference to the underlying GEM object
preventing its destruction.

Signed-off-by: Christian König &lt;christian.koenig@amd.com&gt;
Fixes: c76f0f7cb546 ("drm: Begin an API for in-kernel clients")
Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Tested-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230126102814.8722-1-christian.koenig@amd.com
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/fb-helper: Use a per-driver FB deferred I/O handler</title>
<updated>2023-01-24T10:13:08+00:00</updated>
<author>
<name>Javier Martinez Canillas</name>
<email>javierm@redhat.com</email>
</author>
<published>2023-01-21T19:24:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d6591da5f3ff284a376d56b5f7a48a34e9cb159d'/>
<id>d6591da5f3ff284a376d56b5f7a48a34e9cb159d</id>
<content type='text'>
The DRM fbdev emulation layer sets the struct fb_info .fbdefio field to
a struct fb_deferred_io pointer, that is shared across all drivers that
use the generic drm_fbdev_generic_setup() helper function.

It is a problem because the fbdev core deferred I/O logic assumes that
the struct fb_deferred_io data is not shared between devices, and it's
stored there state such as the list of pages touched and a mutex that
is use to synchronize between the fb_deferred_io_track_page() function
that track the dirty pages and fb_deferred_io_work() workqueue handler
doing the actual deferred I/O.

The latter can lead to the following error, since it may happen that two
drivers are probed and then one is removed, which causes the mutex bo be
destroyed and not existing anymore by the time the other driver tries to
grab it for the fbdev deferred I/O logic:

[  369.756553] ------------[ cut here ]------------
[  369.756604] DEBUG_LOCKS_WARN_ON(lock-&gt;magic != lock)
[  369.756631] WARNING: CPU: 2 PID: 1023 at kernel/locking/mutex.c:582 __mutex_lock+0x348/0x424
[  369.756744] Modules linked in: nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ip
v6 nf_defrag_ipv4 ip_set nf_tables nfnetlink qrtr btsdio bluetooth sunrpc brcmfmac snd_soc_hdmi_codec cpufreq_dt cfg80211 vfat fat vc4 rfkill brcmutil raspberrypi_cpufreq i2c_bcm2835 iproc_rng200 bcm2711_thermal snd_soc_core snd_pcm_dmaen
gine leds_gpio nvmem_rmem joydev hid_cherry uas usb_storage gpio_raspberrypi_exp v3d snd_pcm raspberrypi_hwmon gpu_sched bcm2835_wdt broadcom bcm_phy_lib snd_timer genet snd mdio_bcm_unimac clk_bcm2711_dvp soundcore drm_display_helper pci
e_brcmstb cec ip6_tables ip_tables fuse
[  369.757400] CPU: 2 PID: 1023 Comm: fbtest Not tainted 5.19.0-rc6+ #94
[  369.757455] Hardware name: raspberrypi,4-model-b Raspberry Pi 4 Model B Rev 1.4/Raspberry Pi 4 Model B Rev 1.4, BIOS 2022.10 10/01/2022
[  369.757538] pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  369.757596] pc : __mutex_lock+0x348/0x424
[  369.757635] lr : __mutex_lock+0x348/0x424
[  369.757672] sp : ffff80000953bb00
[  369.757703] x29: ffff80000953bb00 x28: ffff17fdc087c000 x27: 0000000000000002
[  369.757771] x26: ffff17fdc349f9b0 x25: fffffc5ff72e0100 x24: 0000000000000000
[  369.757838] x23: 0000000000000000 x22: 0000000000000002 x21: ffffa618df636f10
[  369.757903] x20: ffff80000953bb68 x19: ffffa618e0f18138 x18: 0000000000000001
[  369.757968] x17: 0000000020000000 x16: 0000000000000002 x15: 0000000000000000
[  369.758032] x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 5f534b434f4c5f47
[  369.758097] x11: 00000000ffffdfff x10: ffffa618e0c79f88 x9 : ffffa618de472484
[  369.758162] x8 : 000000000002ffe8 x7 : c0000000ffffdfff x6 : 00000000000affa8
[  369.758227] x5 : 0000000000001fff x4 : 0000000000000000 x3 : 0000000000000027
[  369.758292] x2 : 0000000000000001 x1 : ffff17fdc087c000 x0 : 0000000000000028
[  369.758357] Call trace:
[  369.758383]  __mutex_lock+0x348/0x424
[  369.758420]  mutex_lock_nested+0x4c/0x5c
[  369.758459]  fb_deferred_io_mkwrite+0x78/0x1d8
[  369.758507]  do_page_mkwrite+0x5c/0x19c
[  369.758550]  wp_page_shared+0x70/0x1a0
[  369.758590]  do_wp_page+0x3d0/0x510
[  369.758628]  handle_pte_fault+0x1c0/0x1e0
[  369.758670]  __handle_mm_fault+0x250/0x380
[  369.758712]  handle_mm_fault+0x17c/0x3a4
[  369.758753]  do_page_fault+0x158/0x530
[  369.758792]  do_mem_abort+0x50/0xa0
[  369.758831]  el0_da+0x78/0x19c
[  369.758864]  el0t_64_sync_handler+0xbc/0x150
[  369.758904]  el0t_64_sync+0x190/0x194
[  369.758942] irq event stamp: 11395
[  369.758973] hardirqs last  enabled at (11395): [&lt;ffffa618de472554&gt;] __up_console_sem+0x74/0x80
[  369.759042] hardirqs last disabled at (11394): [&lt;ffffa618de47254c&gt;] __up_console_sem+0x6c/0x80
[  369.760554] softirqs last  enabled at (11392): [&lt;ffffa618de330a74&gt;] __do_softirq+0x4c4/0x6b8
[  369.762060] softirqs last disabled at (11383): [&lt;ffffa618de3c9124&gt;] __irq_exit_rcu+0x104/0x214
[  369.763564] ---[ end trace 0000000000000000 ]---

Fixes: d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function")
Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230121192418.2814955-4-javierm@redhat.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The DRM fbdev emulation layer sets the struct fb_info .fbdefio field to
a struct fb_deferred_io pointer, that is shared across all drivers that
use the generic drm_fbdev_generic_setup() helper function.

It is a problem because the fbdev core deferred I/O logic assumes that
the struct fb_deferred_io data is not shared between devices, and it's
stored there state such as the list of pages touched and a mutex that
is use to synchronize between the fb_deferred_io_track_page() function
that track the dirty pages and fb_deferred_io_work() workqueue handler
doing the actual deferred I/O.

The latter can lead to the following error, since it may happen that two
drivers are probed and then one is removed, which causes the mutex bo be
destroyed and not existing anymore by the time the other driver tries to
grab it for the fbdev deferred I/O logic:

[  369.756553] ------------[ cut here ]------------
[  369.756604] DEBUG_LOCKS_WARN_ON(lock-&gt;magic != lock)
[  369.756631] WARNING: CPU: 2 PID: 1023 at kernel/locking/mutex.c:582 __mutex_lock+0x348/0x424
[  369.756744] Modules linked in: nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack nf_defrag_ip
v6 nf_defrag_ipv4 ip_set nf_tables nfnetlink qrtr btsdio bluetooth sunrpc brcmfmac snd_soc_hdmi_codec cpufreq_dt cfg80211 vfat fat vc4 rfkill brcmutil raspberrypi_cpufreq i2c_bcm2835 iproc_rng200 bcm2711_thermal snd_soc_core snd_pcm_dmaen
gine leds_gpio nvmem_rmem joydev hid_cherry uas usb_storage gpio_raspberrypi_exp v3d snd_pcm raspberrypi_hwmon gpu_sched bcm2835_wdt broadcom bcm_phy_lib snd_timer genet snd mdio_bcm_unimac clk_bcm2711_dvp soundcore drm_display_helper pci
e_brcmstb cec ip6_tables ip_tables fuse
[  369.757400] CPU: 2 PID: 1023 Comm: fbtest Not tainted 5.19.0-rc6+ #94
[  369.757455] Hardware name: raspberrypi,4-model-b Raspberry Pi 4 Model B Rev 1.4/Raspberry Pi 4 Model B Rev 1.4, BIOS 2022.10 10/01/2022
[  369.757538] pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[  369.757596] pc : __mutex_lock+0x348/0x424
[  369.757635] lr : __mutex_lock+0x348/0x424
[  369.757672] sp : ffff80000953bb00
[  369.757703] x29: ffff80000953bb00 x28: ffff17fdc087c000 x27: 0000000000000002
[  369.757771] x26: ffff17fdc349f9b0 x25: fffffc5ff72e0100 x24: 0000000000000000
[  369.757838] x23: 0000000000000000 x22: 0000000000000002 x21: ffffa618df636f10
[  369.757903] x20: ffff80000953bb68 x19: ffffa618e0f18138 x18: 0000000000000001
[  369.757968] x17: 0000000020000000 x16: 0000000000000002 x15: 0000000000000000
[  369.758032] x14: 0000000000000000 x13: 284e4f5f4e524157 x12: 5f534b434f4c5f47
[  369.758097] x11: 00000000ffffdfff x10: ffffa618e0c79f88 x9 : ffffa618de472484
[  369.758162] x8 : 000000000002ffe8 x7 : c0000000ffffdfff x6 : 00000000000affa8
[  369.758227] x5 : 0000000000001fff x4 : 0000000000000000 x3 : 0000000000000027
[  369.758292] x2 : 0000000000000001 x1 : ffff17fdc087c000 x0 : 0000000000000028
[  369.758357] Call trace:
[  369.758383]  __mutex_lock+0x348/0x424
[  369.758420]  mutex_lock_nested+0x4c/0x5c
[  369.758459]  fb_deferred_io_mkwrite+0x78/0x1d8
[  369.758507]  do_page_mkwrite+0x5c/0x19c
[  369.758550]  wp_page_shared+0x70/0x1a0
[  369.758590]  do_wp_page+0x3d0/0x510
[  369.758628]  handle_pte_fault+0x1c0/0x1e0
[  369.758670]  __handle_mm_fault+0x250/0x380
[  369.758712]  handle_mm_fault+0x17c/0x3a4
[  369.758753]  do_page_fault+0x158/0x530
[  369.758792]  do_mem_abort+0x50/0xa0
[  369.758831]  el0_da+0x78/0x19c
[  369.758864]  el0t_64_sync_handler+0xbc/0x150
[  369.758904]  el0t_64_sync+0x190/0x194
[  369.758942] irq event stamp: 11395
[  369.758973] hardirqs last  enabled at (11395): [&lt;ffffa618de472554&gt;] __up_console_sem+0x74/0x80
[  369.759042] hardirqs last disabled at (11394): [&lt;ffffa618de47254c&gt;] __up_console_sem+0x6c/0x80
[  369.760554] softirqs last  enabled at (11392): [&lt;ffffa618de330a74&gt;] __do_softirq+0x4c4/0x6b8
[  369.762060] softirqs last disabled at (11383): [&lt;ffffa618de3c9124&gt;] __irq_exit_rcu+0x104/0x214
[  369.763564] ---[ end trace 0000000000000000 ]---

Fixes: d536540f304c ("drm/fb-helper: Add generic fbdev emulation .fb_probe function")
Signed-off-by: Javier Martinez Canillas &lt;javierm@redhat.com&gt;
Reviewed-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20230121192418.2814955-4-javierm@redhat.com
</pre>
</div>
</content>
</entry>
<entry>
<title>drm/drm_vma_manager: Add drm_vma_node_allow_once()</title>
<updated>2023-01-19T13:16:55+00:00</updated>
<author>
<name>Nirmoy Das</name>
<email>nirmoy.das@intel.com</email>
</author>
<published>2023-01-17T17:52:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=899d3a3c19ac0e5da013ce34833dccb97d19b5e4'/>
<id>899d3a3c19ac0e5da013ce34833dccb97d19b5e4</id>
<content type='text'>
Currently there is no easy way for a drm driver to safely check and allow
drm_vma_offset_node for a drm file just once. Allow drm drivers to call
non-refcounted version of drm_vma_node_allow() so that a driver doesn't
need to keep track of each drm_vma_node_allow() to call subsequent
drm_vma_node_revoke() to prevent memory leak.

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: Tvrtko Ursulin &lt;tvrtko.ursulin@linux.intel.com&gt;
Cc: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;

Suggested-by: Chris Wilson &lt;chris.p.wilson@intel.com&gt;
Signed-off-by: Nirmoy Das &lt;nirmoy.das@intel.com&gt;
Reviewed-by: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Reviewed-by: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230117175236.22317-1-nirmoy.das@intel.com
Signed-off-by: Maxime Ripard &lt;maxime@cerno.tech&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently there is no easy way for a drm driver to safely check and allow
drm_vma_offset_node for a drm file just once. Allow drm drivers to call
non-refcounted version of drm_vma_node_allow() so that a driver doesn't
need to keep track of each drm_vma_node_allow() to call subsequent
drm_vma_node_revoke() to prevent memory leak.

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: Tvrtko Ursulin &lt;tvrtko.ursulin@linux.intel.com&gt;
Cc: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;

Suggested-by: Chris Wilson &lt;chris.p.wilson@intel.com&gt;
Signed-off-by: Nirmoy Das &lt;nirmoy.das@intel.com&gt;
Reviewed-by: Tvrtko Ursulin &lt;tvrtko.ursulin@intel.com&gt;
Reviewed-by: Andi Shyti &lt;andi.shyti@linux.intel.com&gt;
Link: https://lore.kernel.org/r/20230117175236.22317-1-nirmoy.das@intel.com
Signed-off-by: Maxime Ripard &lt;maxime@cerno.tech&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge drm/drm-fixes into drm-misc-fixes</title>
<updated>2023-01-03T07:32:12+00:00</updated>
<author>
<name>Maxime Ripard</name>
<email>maxime@cerno.tech</email>
</author>
<published>2023-01-03T07:32:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2c55d703391acf7e9101da596d0c15ee03b318a3'/>
<id>2c55d703391acf7e9101da596d0c15ee03b318a3</id>
<content type='text'>
Let's start the fixes cycle.

Signed-off-by: Maxime Ripard &lt;maxime@cerno.tech&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Let's start the fixes cycle.

Signed-off-by: Maxime Ripard &lt;maxime@cerno.tech&gt;
</pre>
</div>
</content>
</entry>
</feed>
