<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/video/fbdev, branch linux-6.13.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>fbdev: omapfb: Add 'plane' value check</title>
<updated>2025-04-20T08:17:52+00:00</updated>
<author>
<name>Leonid Arapov</name>
<email>arapovl839@gmail.com</email>
</author>
<published>2025-03-18T21:19:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9b0a41589ee70529b20e1e0108d03f10c649bdc4'/>
<id>9b0a41589ee70529b20e1e0108d03f10c649bdc4</id>
<content type='text'>
[ Upstream commit 3e411827f31db7f938a30a3c7a7599839401ec30 ]

Function dispc_ovl_setup is not intended to work with the value OMAP_DSS_WB
of the enum parameter plane.

The value of this parameter is initialized in dss_init_overlays and in the
current state of the code it cannot take this value so it's not a real
problem.

For the purposes of defensive coding it wouldn't be superfluous to check
the parameter value, because some functions down the call stack process
this value correctly and some not.

For example, in dispc_ovl_setup_global_alpha it may lead to buffer
overflow.

Add check for this value.

Found by Linux Verification Center (linuxtesting.org) with SVACE static
analysis tool.

Signed-off-by: Leonid Arapov &lt;arapovl839@gmail.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 3e411827f31db7f938a30a3c7a7599839401ec30 ]

Function dispc_ovl_setup is not intended to work with the value OMAP_DSS_WB
of the enum parameter plane.

The value of this parameter is initialized in dss_init_overlays and in the
current state of the code it cannot take this value so it's not a real
problem.

For the purposes of defensive coding it wouldn't be superfluous to check
the parameter value, because some functions down the call stack process
this value correctly and some not.

For example, in dispc_ovl_setup_global_alpha it may lead to buffer
overflow.

Add check for this value.

Found by Linux Verification Center (linuxtesting.org) with SVACE static
analysis tool.

Signed-off-by: Leonid Arapov &lt;arapovl839@gmail.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: sm501fb: Add some geometry checks.</title>
<updated>2025-04-10T12:41:39+00:00</updated>
<author>
<name>Danila Chernetsov</name>
<email>listdansp@mail.ru</email>
</author>
<published>2025-03-19T01:30:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b97344d56fec71c4c980f01a0764006128d1a8b1'/>
<id>b97344d56fec71c4c980f01a0764006128d1a8b1</id>
<content type='text'>
[ Upstream commit aee50bd88ea5fde1ff4cc021385598f81a65830c ]

Added checks for xoffset, yoffset settings.
Incorrect settings of these parameters can lead to errors
in sm501fb_pan_ functions.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 5fc404e47bdf ("[PATCH] fb: SM501 framebuffer driver")
Signed-off-by: Danila Chernetsov &lt;listdansp@mail.ru&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 aee50bd88ea5fde1ff4cc021385598f81a65830c ]

Added checks for xoffset, yoffset settings.
Incorrect settings of these parameters can lead to errors
in sm501fb_pan_ functions.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 5fc404e47bdf ("[PATCH] fb: SM501 framebuffer driver")
Signed-off-by: Danila Chernetsov &lt;listdansp@mail.ru&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: au1100fb: Move a variable assignment behind a null pointer check</title>
<updated>2025-04-10T12:41:39+00:00</updated>
<author>
<name>Markus Elfring</name>
<email>elfring@users.sourceforge.net</email>
</author>
<published>2023-04-13T19:35:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=26ed066f362cf783549293840e719c56e29ed137'/>
<id>26ed066f362cf783549293840e719c56e29ed137</id>
<content type='text'>
[ Upstream commit 2df2c0caaecfd869b49e14f2b8df822397c5dd7f ]

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “au1100fb_setmode”.

This issue was detected by using the Coccinelle software.

Fixes: 3b495f2bb749 ("Au1100 FB driver uplift for 2.6.")
Signed-off-by: Markus Elfring &lt;elfring@users.sourceforge.net&gt;
Acked-by: Uwe Kleine-König &lt;u.kleine-koenig@baylibre.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 2df2c0caaecfd869b49e14f2b8df822397c5dd7f ]

The address of a data structure member was determined before
a corresponding null pointer check in the implementation of
the function “au1100fb_setmode”.

This issue was detected by using the Coccinelle software.

Fixes: 3b495f2bb749 ("Au1100 FB driver uplift for 2.6.")
Signed-off-by: Markus Elfring &lt;elfring@users.sourceforge.net&gt;
Acked-by: Uwe Kleine-König &lt;u.kleine-koenig@baylibre.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: hyperv_fb: Allow graceful removal of framebuffer</title>
<updated>2025-03-22T19:56:42+00:00</updated>
<author>
<name>Saurabh Sengar</name>
<email>ssengar@linux.microsoft.com</email>
</author>
<published>2025-03-01T16:16:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a7b583dc99c6cf4a96877017be1d08247e1ef2c7'/>
<id>a7b583dc99c6cf4a96877017be1d08247e1ef2c7</id>
<content type='text'>
[ Upstream commit ea2f45ab0e53b255f72c85ccd99e2b394fc5fceb ]

When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to
release the framebuffer forcefully. If this framebuffer is in use it
produce the following WARN and hence this framebuffer is never released.

[   44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40
&lt; snip &gt;
[   44.111289] Call Trace:
[   44.111290]  &lt;TASK&gt;
[   44.111291]  ? show_regs+0x6c/0x80
[   44.111295]  ? __warn+0x8d/0x150
[   44.111298]  ? framebuffer_release+0x2c/0x40
[   44.111300]  ? report_bug+0x182/0x1b0
[   44.111303]  ? handle_bug+0x6e/0xb0
[   44.111306]  ? exc_invalid_op+0x18/0x80
[   44.111308]  ? asm_exc_invalid_op+0x1b/0x20
[   44.111311]  ? framebuffer_release+0x2c/0x40
[   44.111313]  ? hvfb_remove+0x86/0xa0 [hyperv_fb]
[   44.111315]  vmbus_remove+0x24/0x40 [hv_vmbus]
[   44.111323]  device_remove+0x40/0x80
[   44.111325]  device_release_driver_internal+0x20b/0x270
[   44.111327]  ? bus_find_device+0xb3/0xf0

Fix this by moving the release of framebuffer and assosiated memory
to fb_ops.fb_destroy function, so that framebuffer framework handles
it gracefully.

While we fix this, also replace manual registrations/unregistration of
framebuffer with devm_register_framebuffer.

Fixes: 68a2d20b79b1 ("drivers/video: add Hyper-V Synthetic Video Frame Buffer Driver")

Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1740845791-19977-3-git-send-email-ssengar@linux.microsoft.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 ea2f45ab0e53b255f72c85ccd99e2b394fc5fceb ]

When a Hyper-V framebuffer device is unbind, hyperv_fb driver tries to
release the framebuffer forcefully. If this framebuffer is in use it
produce the following WARN and hence this framebuffer is never released.

[   44.111220] WARNING: CPU: 35 PID: 1882 at drivers/video/fbdev/core/fb_info.c:70 framebuffer_release+0x2c/0x40
&lt; snip &gt;
[   44.111289] Call Trace:
[   44.111290]  &lt;TASK&gt;
[   44.111291]  ? show_regs+0x6c/0x80
[   44.111295]  ? __warn+0x8d/0x150
[   44.111298]  ? framebuffer_release+0x2c/0x40
[   44.111300]  ? report_bug+0x182/0x1b0
[   44.111303]  ? handle_bug+0x6e/0xb0
[   44.111306]  ? exc_invalid_op+0x18/0x80
[   44.111308]  ? asm_exc_invalid_op+0x1b/0x20
[   44.111311]  ? framebuffer_release+0x2c/0x40
[   44.111313]  ? hvfb_remove+0x86/0xa0 [hyperv_fb]
[   44.111315]  vmbus_remove+0x24/0x40 [hv_vmbus]
[   44.111323]  device_remove+0x40/0x80
[   44.111325]  device_release_driver_internal+0x20b/0x270
[   44.111327]  ? bus_find_device+0xb3/0xf0

Fix this by moving the release of framebuffer and assosiated memory
to fb_ops.fb_destroy function, so that framebuffer framework handles
it gracefully.

While we fix this, also replace manual registrations/unregistration of
framebuffer with devm_register_framebuffer.

Fixes: 68a2d20b79b1 ("drivers/video: add Hyper-V Synthetic Video Frame Buffer Driver")

Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1740845791-19977-3-git-send-email-ssengar@linux.microsoft.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: hyperv_fb: Simplify hvfb_putmem</title>
<updated>2025-03-22T19:56:42+00:00</updated>
<author>
<name>Saurabh Sengar</name>
<email>ssengar@linux.microsoft.com</email>
</author>
<published>2025-03-01T16:16:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d486d3c6295e3e2a890ba96422b8df16cdae4510'/>
<id>d486d3c6295e3e2a890ba96422b8df16cdae4510</id>
<content type='text'>
[ Upstream commit f5e728a50bb17336a20803dde488515b833ecd1d ]

The device object required in 'hvfb_release_phymem' function
for 'dma_free_coherent' can also be obtained from the 'info'
pointer, making 'hdev' parameter in 'hvfb_putmem' redundant.
Remove the unnecessary 'hdev' argument from 'hvfb_putmem'.

Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1740845791-19977-2-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1740845791-19977-2-git-send-email-ssengar@linux.microsoft.com&gt;
Stable-dep-of: ea2f45ab0e53 ("fbdev: hyperv_fb: Allow graceful removal of framebuffer")
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 f5e728a50bb17336a20803dde488515b833ecd1d ]

The device object required in 'hvfb_release_phymem' function
for 'dma_free_coherent' can also be obtained from the 'info'
pointer, making 'hdev' parameter in 'hvfb_putmem' redundant.
Remove the unnecessary 'hdev' argument from 'hvfb_putmem'.

Signed-off-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Reviewed-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Tested-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/1740845791-19977-2-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;1740845791-19977-2-git-send-email-ssengar@linux.microsoft.com&gt;
Stable-dep-of: ea2f45ab0e53 ("fbdev: hyperv_fb: Allow graceful removal of framebuffer")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: hyperv_fb: Fix hang in kdump kernel when on Hyper-V Gen 2 VMs</title>
<updated>2025-03-22T19:56:41+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mhklinux@outlook.com</email>
</author>
<published>2025-02-18T23:01:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2924802d35e00a36b1503a4e786f1926b2fdc1d0'/>
<id>2924802d35e00a36b1503a4e786f1926b2fdc1d0</id>
<content type='text'>
[ Upstream commit 304386373007aaca9236a3f36afac0bbedcd2bf0 ]

Gen 2 Hyper-V VMs boot via EFI and have a standard EFI framebuffer
device. When the kdump kernel runs in such a VM, loading the efifb
driver may hang because of accessing the framebuffer at the wrong
memory address.

The scenario occurs when the hyperv_fb driver in the original kernel
moves the framebuffer to a different MMIO address because of conflicts
with an already-running efifb or simplefb driver. The hyperv_fb driver
then informs Hyper-V of the change, which is allowed by the Hyper-V FB
VMBus device protocol. However, when the kexec command loads the kdump
kernel into crash memory via the kexec_file_load() system call, the
system call doesn't know the framebuffer has moved, and it sets up the
kdump screen_info using the original framebuffer address. The transition
to the kdump kernel does not go through the Hyper-V host, so Hyper-V
does not reset the framebuffer address like it would do on a reboot.
When efifb tries to run, it accesses a non-existent framebuffer
address, which traps to the Hyper-V host. After many such accesses,
the Hyper-V host thinks the guest is being malicious, and throttles
the guest to the point that it runs very slowly or appears to have hung.

When the kdump kernel is loaded into crash memory via the kexec_load()
system call, the problem does not occur. In this case, the kexec command
builds the screen_info table itself in user space from data returned
by the FBIOGET_FSCREENINFO ioctl against /dev/fb0, which gives it the
new framebuffer location.

This problem was originally reported in 2020 [1], resulting in commit
3cb73bc3fa2a ("hyperv_fb: Update screen_info after removing old
framebuffer"). This commit solved the problem by setting orig_video_isVGA
to 0, so the kdump kernel was unaware of the EFI framebuffer. The efifb
driver did not try to load, and no hang occurred. But in 2024, commit
c25a19afb81c ("fbdev/hyperv_fb: Do not clear global screen_info")
effectively reverted 3cb73bc3fa2a. Commit c25a19afb81c has no reference
to 3cb73bc3fa2a, so perhaps it was done without knowing the implications
that were reported with 3cb73bc3fa2a. In any case, as of commit
c25a19afb81c, the original problem came back again.

Interestingly, the hyperv_drm driver does not have this problem because
it never moves the framebuffer. The difference is that the hyperv_drm
driver removes any conflicting framebuffers *before* allocating an MMIO
address, while the hyperv_fb drivers removes conflicting framebuffers
*after* allocating an MMIO address. With the "after" ordering, hyperv_fb
may encounter a conflict and move the framebuffer to a different MMIO
address. But the conflict is essentially bogus because it is removed
a few lines of code later.

Rather than fix the problem with the approach from 2020 in commit
3cb73bc3fa2a, instead slightly reorder the steps in hyperv_fb so
conflicting framebuffers are removed before allocating an MMIO address.
Then the default framebuffer MMIO address should always be available, and
there's never any confusion about which framebuffer address the kdump
kernel should use -- it's always the original address provided by
the Hyper-V host. This approach is already used by the hyperv_drm
driver, and is consistent with the usage guidelines at the head of
the module with the function aperture_remove_conflicting_devices().

This approach also solves a related minor problem when kexec_load()
is used to load the kdump kernel. With current code, unbinding and
rebinding the hyperv_fb driver could result in the framebuffer moving
back to the default framebuffer address, because on the rebind there
are no conflicts. If such a move is done after the kdump kernel is
loaded with the new framebuffer address, at kdump time it could again
have the wrong address.

This problem and fix are described in terms of the kdump kernel, but
it can also occur with any kernel started via kexec.

See extensive discussion of the problem and solution at [2].

[1] https://lore.kernel.org/linux-hyperv/20201014092429.1415040-1-kasong@redhat.com/
[2] https://lore.kernel.org/linux-hyperv/BLAPR10MB521793485093FDB448F7B2E5FDE92@BLAPR10MB5217.namprd10.prod.outlook.com/

Reported-by: Thomas Tai &lt;thomas.tai@oracle.com&gt;
Fixes: c25a19afb81c ("fbdev/hyperv_fb: Do not clear global screen_info")
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/20250218230130.3207-1-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20250218230130.3207-1-mhklinux@outlook.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 304386373007aaca9236a3f36afac0bbedcd2bf0 ]

Gen 2 Hyper-V VMs boot via EFI and have a standard EFI framebuffer
device. When the kdump kernel runs in such a VM, loading the efifb
driver may hang because of accessing the framebuffer at the wrong
memory address.

The scenario occurs when the hyperv_fb driver in the original kernel
moves the framebuffer to a different MMIO address because of conflicts
with an already-running efifb or simplefb driver. The hyperv_fb driver
then informs Hyper-V of the change, which is allowed by the Hyper-V FB
VMBus device protocol. However, when the kexec command loads the kdump
kernel into crash memory via the kexec_file_load() system call, the
system call doesn't know the framebuffer has moved, and it sets up the
kdump screen_info using the original framebuffer address. The transition
to the kdump kernel does not go through the Hyper-V host, so Hyper-V
does not reset the framebuffer address like it would do on a reboot.
When efifb tries to run, it accesses a non-existent framebuffer
address, which traps to the Hyper-V host. After many such accesses,
the Hyper-V host thinks the guest is being malicious, and throttles
the guest to the point that it runs very slowly or appears to have hung.

When the kdump kernel is loaded into crash memory via the kexec_load()
system call, the problem does not occur. In this case, the kexec command
builds the screen_info table itself in user space from data returned
by the FBIOGET_FSCREENINFO ioctl against /dev/fb0, which gives it the
new framebuffer location.

This problem was originally reported in 2020 [1], resulting in commit
3cb73bc3fa2a ("hyperv_fb: Update screen_info after removing old
framebuffer"). This commit solved the problem by setting orig_video_isVGA
to 0, so the kdump kernel was unaware of the EFI framebuffer. The efifb
driver did not try to load, and no hang occurred. But in 2024, commit
c25a19afb81c ("fbdev/hyperv_fb: Do not clear global screen_info")
effectively reverted 3cb73bc3fa2a. Commit c25a19afb81c has no reference
to 3cb73bc3fa2a, so perhaps it was done without knowing the implications
that were reported with 3cb73bc3fa2a. In any case, as of commit
c25a19afb81c, the original problem came back again.

Interestingly, the hyperv_drm driver does not have this problem because
it never moves the framebuffer. The difference is that the hyperv_drm
driver removes any conflicting framebuffers *before* allocating an MMIO
address, while the hyperv_fb drivers removes conflicting framebuffers
*after* allocating an MMIO address. With the "after" ordering, hyperv_fb
may encounter a conflict and move the framebuffer to a different MMIO
address. But the conflict is essentially bogus because it is removed
a few lines of code later.

Rather than fix the problem with the approach from 2020 in commit
3cb73bc3fa2a, instead slightly reorder the steps in hyperv_fb so
conflicting framebuffers are removed before allocating an MMIO address.
Then the default framebuffer MMIO address should always be available, and
there's never any confusion about which framebuffer address the kdump
kernel should use -- it's always the original address provided by
the Hyper-V host. This approach is already used by the hyperv_drm
driver, and is consistent with the usage guidelines at the head of
the module with the function aperture_remove_conflicting_devices().

This approach also solves a related minor problem when kexec_load()
is used to load the kdump kernel. With current code, unbinding and
rebinding the hyperv_fb driver could result in the framebuffer moving
back to the default framebuffer address, because on the rebind there
are no conflicts. If such a move is done after the kdump kernel is
loaded with the new framebuffer address, at kdump time it could again
have the wrong address.

This problem and fix are described in terms of the kdump kernel, but
it can also occur with any kernel started via kexec.

See extensive discussion of the problem and solution at [2].

[1] https://lore.kernel.org/linux-hyperv/20201014092429.1415040-1-kasong@redhat.com/
[2] https://lore.kernel.org/linux-hyperv/BLAPR10MB521793485093FDB448F7B2E5FDE92@BLAPR10MB5217.namprd10.prod.outlook.com/

Reported-by: Thomas Tai &lt;thomas.tai@oracle.com&gt;
Fixes: c25a19afb81c ("fbdev/hyperv_fb: Do not clear global screen_info")
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Link: https://lore.kernel.org/r/20250218230130.3207-1-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20250218230130.3207-1-mhklinux@outlook.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: hyperv_fb: iounmap() the correct memory when removing a device</title>
<updated>2025-03-22T19:56:39+00:00</updated>
<author>
<name>Michael Kelley</name>
<email>mhklinux@outlook.com</email>
</author>
<published>2025-02-09T23:52:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f4e830b59856677957b1d2e6034606b4432fb9ef'/>
<id>f4e830b59856677957b1d2e6034606b4432fb9ef</id>
<content type='text'>
[ Upstream commit 7241c886a71797cc51efc6fadec7076fcf6435c2 ]

When a Hyper-V framebuffer device is removed, or the driver is unbound
from a device, any allocated and/or mapped memory must be released. In
particular, MMIO address space that was mapped to the framebuffer must
be unmapped. Current code unmaps the wrong address, resulting in an
error like:

[ 4093.980597] iounmap: bad address 00000000c936c05c

followed by a stack dump.

Commit d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for
Hyper-V frame buffer driver") changed the kind of address stored in
info-&gt;screen_base, and the iounmap() call in hvfb_putmem() was not
updated accordingly.

Fix this by updating hvfb_putmem() to unmap the correct address.

Fixes: d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver")
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20250209235252.2987-1-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20250209235252.2987-1-mhklinux@outlook.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 7241c886a71797cc51efc6fadec7076fcf6435c2 ]

When a Hyper-V framebuffer device is removed, or the driver is unbound
from a device, any allocated and/or mapped memory must be released. In
particular, MMIO address space that was mapped to the framebuffer must
be unmapped. Current code unmaps the wrong address, resulting in an
error like:

[ 4093.980597] iounmap: bad address 00000000c936c05c

followed by a stack dump.

Commit d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for
Hyper-V frame buffer driver") changed the kind of address stored in
info-&gt;screen_base, and the iounmap() call in hvfb_putmem() was not
updated accordingly.

Fix this by updating hvfb_putmem() to unmap the correct address.

Fixes: d21987d709e8 ("video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver")
Signed-off-by: Michael Kelley &lt;mhklinux@outlook.com&gt;
Reviewed-by: Saurabh Sengar &lt;ssengar@linux.microsoft.com&gt;
Link: https://lore.kernel.org/r/20250209235252.2987-1-mhklinux@outlook.com
Signed-off-by: Wei Liu &lt;wei.liu@kernel.org&gt;
Message-ID: &lt;20250209235252.2987-1-mhklinux@outlook.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: omap: use threaded IRQ for LCD DMA</title>
<updated>2025-02-21T13:10:52+00:00</updated>
<author>
<name>Aaro Koskinen</name>
<email>aaro.koskinen@iki.fi</email>
</author>
<published>2025-01-02T18:19:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8392ea100f0b86c234c739c6662f39f0ccc0cefd'/>
<id>8392ea100f0b86c234c739c6662f39f0ccc0cefd</id>
<content type='text'>
[ Upstream commit e4b6b665df815b4841e71b72f06446884e8aad40 ]

When using touchscreen and framebuffer, Nokia 770 crashes easily with:

    BUG: scheduling while atomic: irq/144-ads7846/82/0x00010000
    Modules linked in: usb_f_ecm g_ether usb_f_rndis u_ether libcomposite configfs omap_udc ohci_omap ohci_hcd
    CPU: 0 UID: 0 PID: 82 Comm: irq/144-ads7846 Not tainted 6.12.7-770 #2
    Hardware name: Nokia 770
    Call trace:
     unwind_backtrace from show_stack+0x10/0x14
     show_stack from dump_stack_lvl+0x54/0x5c
     dump_stack_lvl from __schedule_bug+0x50/0x70
     __schedule_bug from __schedule+0x4d4/0x5bc
     __schedule from schedule+0x34/0xa0
     schedule from schedule_preempt_disabled+0xc/0x10
     schedule_preempt_disabled from __mutex_lock.constprop.0+0x218/0x3b4
     __mutex_lock.constprop.0 from clk_prepare_lock+0x38/0xe4
     clk_prepare_lock from clk_set_rate+0x18/0x154
     clk_set_rate from sossi_read_data+0x4c/0x168
     sossi_read_data from hwa742_read_reg+0x5c/0x8c
     hwa742_read_reg from send_frame_handler+0xfc/0x300
     send_frame_handler from process_pending_requests+0x74/0xd0
     process_pending_requests from lcd_dma_irq_handler+0x50/0x74
     lcd_dma_irq_handler from __handle_irq_event_percpu+0x44/0x130
     __handle_irq_event_percpu from handle_irq_event+0x28/0x68
     handle_irq_event from handle_level_irq+0x9c/0x170
     handle_level_irq from generic_handle_domain_irq+0x2c/0x3c
     generic_handle_domain_irq from omap1_handle_irq+0x40/0x8c
     omap1_handle_irq from generic_handle_arch_irq+0x28/0x3c
     generic_handle_arch_irq from call_with_stack+0x1c/0x24
     call_with_stack from __irq_svc+0x94/0xa8
    Exception stack(0xc5255da0 to 0xc5255de8)
    5da0: 00000001 c22fc620 00000000 00000000 c08384a8 c106fc00 00000000 c240c248
    5dc0: c113a600 c3f6ec30 00000001 00000000 c22fc620 c5255df0 c22fc620 c0279a94
    5de0: 60000013 ffffffff
     __irq_svc from clk_prepare_lock+0x4c/0xe4
     clk_prepare_lock from clk_get_rate+0x10/0x74
     clk_get_rate from uwire_setup_transfer+0x40/0x180
     uwire_setup_transfer from spi_bitbang_transfer_one+0x2c/0x9c
     spi_bitbang_transfer_one from spi_transfer_one_message+0x2d0/0x664
     spi_transfer_one_message from __spi_pump_transfer_message+0x29c/0x498
     __spi_pump_transfer_message from __spi_sync+0x1f8/0x2e8
     __spi_sync from spi_sync+0x24/0x40
     spi_sync from ads7846_halfd_read_state+0x5c/0x1c0
     ads7846_halfd_read_state from ads7846_irq+0x58/0x348
     ads7846_irq from irq_thread_fn+0x1c/0x78
     irq_thread_fn from irq_thread+0x120/0x228
     irq_thread from kthread+0xc8/0xe8
     kthread from ret_from_fork+0x14/0x28

As a quick fix, switch to a threaded IRQ which provides a stable system.

Signed-off-by: Aaro Koskinen &lt;aaro.koskinen@iki.fi&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 e4b6b665df815b4841e71b72f06446884e8aad40 ]

When using touchscreen and framebuffer, Nokia 770 crashes easily with:

    BUG: scheduling while atomic: irq/144-ads7846/82/0x00010000
    Modules linked in: usb_f_ecm g_ether usb_f_rndis u_ether libcomposite configfs omap_udc ohci_omap ohci_hcd
    CPU: 0 UID: 0 PID: 82 Comm: irq/144-ads7846 Not tainted 6.12.7-770 #2
    Hardware name: Nokia 770
    Call trace:
     unwind_backtrace from show_stack+0x10/0x14
     show_stack from dump_stack_lvl+0x54/0x5c
     dump_stack_lvl from __schedule_bug+0x50/0x70
     __schedule_bug from __schedule+0x4d4/0x5bc
     __schedule from schedule+0x34/0xa0
     schedule from schedule_preempt_disabled+0xc/0x10
     schedule_preempt_disabled from __mutex_lock.constprop.0+0x218/0x3b4
     __mutex_lock.constprop.0 from clk_prepare_lock+0x38/0xe4
     clk_prepare_lock from clk_set_rate+0x18/0x154
     clk_set_rate from sossi_read_data+0x4c/0x168
     sossi_read_data from hwa742_read_reg+0x5c/0x8c
     hwa742_read_reg from send_frame_handler+0xfc/0x300
     send_frame_handler from process_pending_requests+0x74/0xd0
     process_pending_requests from lcd_dma_irq_handler+0x50/0x74
     lcd_dma_irq_handler from __handle_irq_event_percpu+0x44/0x130
     __handle_irq_event_percpu from handle_irq_event+0x28/0x68
     handle_irq_event from handle_level_irq+0x9c/0x170
     handle_level_irq from generic_handle_domain_irq+0x2c/0x3c
     generic_handle_domain_irq from omap1_handle_irq+0x40/0x8c
     omap1_handle_irq from generic_handle_arch_irq+0x28/0x3c
     generic_handle_arch_irq from call_with_stack+0x1c/0x24
     call_with_stack from __irq_svc+0x94/0xa8
    Exception stack(0xc5255da0 to 0xc5255de8)
    5da0: 00000001 c22fc620 00000000 00000000 c08384a8 c106fc00 00000000 c240c248
    5dc0: c113a600 c3f6ec30 00000001 00000000 c22fc620 c5255df0 c22fc620 c0279a94
    5de0: 60000013 ffffffff
     __irq_svc from clk_prepare_lock+0x4c/0xe4
     clk_prepare_lock from clk_get_rate+0x10/0x74
     clk_get_rate from uwire_setup_transfer+0x40/0x180
     uwire_setup_transfer from spi_bitbang_transfer_one+0x2c/0x9c
     spi_bitbang_transfer_one from spi_transfer_one_message+0x2d0/0x664
     spi_transfer_one_message from __spi_pump_transfer_message+0x29c/0x498
     __spi_pump_transfer_message from __spi_sync+0x1f8/0x2e8
     __spi_sync from spi_sync+0x24/0x40
     spi_sync from ads7846_halfd_read_state+0x5c/0x1c0
     ads7846_halfd_read_state from ads7846_irq+0x58/0x348
     ads7846_irq from irq_thread_fn+0x1c/0x78
     irq_thread_fn from irq_thread+0x120/0x228
     irq_thread from kthread+0xc8/0xe8
     kthread from ret_from_fork+0x14/0x28

As a quick fix, switch to a threaded IRQ which provides a stable system.

Signed-off-by: Aaro Koskinen &lt;aaro.koskinen@iki.fi&gt;
Reviewed-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: omapfb: Fix an OF node leak in dss_of_port_get_parent_device()</title>
<updated>2025-02-08T09:01:57+00:00</updated>
<author>
<name>Joe Hattori</name>
<email>joe@pf.is.s.u-tokyo.ac.jp</email>
</author>
<published>2025-01-08T01:15:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eea357f2b70af2522439215f755bcc89cbaef24f'/>
<id>eea357f2b70af2522439215f755bcc89cbaef24f</id>
<content type='text'>
[ Upstream commit de124b61e179e690277116e6be512e4f422b5dd8 ]

dss_of_port_get_parent_device() leaks an OF node reference when i &gt;= 2
and struct device_node *np is present. Since of_get_next_parent()
obtains a reference of the returned OF node, call of_node_put() before
returning NULL.

This was found by an experimental verifier that I am developing, and no
runtime test was able to be performed due to that lack of actual
devices.

Fixes: f76ee892a99e ("omapfb: copy omapdss &amp; displays for omapfb")
Signed-off-by: Joe Hattori &lt;joe@pf.is.s.u-tokyo.ac.jp&gt;
Reviewed-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&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 de124b61e179e690277116e6be512e4f422b5dd8 ]

dss_of_port_get_parent_device() leaks an OF node reference when i &gt;= 2
and struct device_node *np is present. Since of_get_next_parent()
obtains a reference of the returned OF node, call of_node_put() before
returning NULL.

This was found by an experimental verifier that I am developing, and no
runtime test was able to be performed due to that lack of actual
devices.

Fixes: f76ee892a99e ("omapfb: copy omapdss &amp; displays for omapfb")
Signed-off-by: Joe Hattori &lt;joe@pf.is.s.u-tokyo.ac.jp&gt;
Reviewed-by: Laurent Pinchart &lt;laurent.pinchart@ideasonboard.com&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fbdev: Fix recursive dependencies wrt BACKLIGHT_CLASS_DEVICE</title>
<updated>2024-12-17T17:06:10+00:00</updated>
<author>
<name>Thomas Zimmermann</name>
<email>tzimmermann@suse.de</email>
</author>
<published>2024-12-16T07:42:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8fc38062be3f692ff8816da84fde71972530bcc4'/>
<id>8fc38062be3f692ff8816da84fde71972530bcc4</id>
<content type='text'>
Do not select BACKLIGHT_CLASS_DEVICE from FB_BACKLIGHT. The latter
only controls backlight support within fbdev core code and data
structures.

Make fbdev drivers depend on BACKLIGHT_CLASS_DEVICE and let users
select it explicitly. Fixes warnings about recursive dependencies,
such as

error: recursive dependency detected!
	symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT
	symbol FB_BACKLIGHT is selected by FB_SH_MOBILE_LCDC
	symbol FB_SH_MOBILE_LCDC depends on FB_DEVICE
	symbol FB_DEVICE depends on FB_CORE
	symbol FB_CORE is selected by DRM_GEM_DMA_HELPER
	symbol DRM_GEM_DMA_HELPER is selected by DRM_PANEL_ILITEK_ILI9341
	symbol DRM_PANEL_ILITEK_ILI9341 depends on BACKLIGHT_CLASS_DEVICE

BACKLIGHT_CLASS_DEVICE is user-selectable, so making drivers adapt to
it is the correct approach in any case. For most drivers, backlight
support is also configurable separately.

v3:
- Select BACKLIGHT_CLASS_DEVICE in PowerMac defconfigs (Christophe)
- Fix PMAC_BACKLIGHT module dependency corner cases (Christophe)
v2:
- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)
- Fix fbdev driver-dependency corner case (Arnd)

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20241216074450.8590-2-tzimmermann@suse.de
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Do not select BACKLIGHT_CLASS_DEVICE from FB_BACKLIGHT. The latter
only controls backlight support within fbdev core code and data
structures.

Make fbdev drivers depend on BACKLIGHT_CLASS_DEVICE and let users
select it explicitly. Fixes warnings about recursive dependencies,
such as

error: recursive dependency detected!
	symbol BACKLIGHT_CLASS_DEVICE is selected by FB_BACKLIGHT
	symbol FB_BACKLIGHT is selected by FB_SH_MOBILE_LCDC
	symbol FB_SH_MOBILE_LCDC depends on FB_DEVICE
	symbol FB_DEVICE depends on FB_CORE
	symbol FB_CORE is selected by DRM_GEM_DMA_HELPER
	symbol DRM_GEM_DMA_HELPER is selected by DRM_PANEL_ILITEK_ILI9341
	symbol DRM_PANEL_ILITEK_ILI9341 depends on BACKLIGHT_CLASS_DEVICE

BACKLIGHT_CLASS_DEVICE is user-selectable, so making drivers adapt to
it is the correct approach in any case. For most drivers, backlight
support is also configurable separately.

v3:
- Select BACKLIGHT_CLASS_DEVICE in PowerMac defconfigs (Christophe)
- Fix PMAC_BACKLIGHT module dependency corner cases (Christophe)
v2:
- s/BACKLIGHT_DEVICE_CLASS/BACKLIGHT_CLASS_DEVICE (Helge)
- Fix fbdev driver-dependency corner case (Arnd)

Signed-off-by: Thomas Zimmermann &lt;tzimmermann@suse.de&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Link: https://patchwork.freedesktop.org/patch/msgid/20241216074450.8590-2-tzimmermann@suse.de
</pre>
</div>
</content>
</entry>
</feed>
