<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/acpi, branch linux-4.9.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ACPICA: Fix error code path in acpi_ds_call_control_method()</title>
<updated>2023-01-07T11:07:31+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-11-07T17:42:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=38e251d356a01b61a86cb35213cafd7e8fe7090c'/>
<id>38e251d356a01b61a86cb35213cafd7e8fe7090c</id>
<content type='text'>
[ Upstream commit 404ec60438add1afadaffaed34bb5fe4ddcadd40 ]

A use-after-free in acpi_ps_parse_aml() after a failing invocaion of
acpi_ds_call_control_method() is reported by KASAN [1] and code
inspection reveals that next_walk_state pushed to the thread by
acpi_ds_create_walk_state() is freed on errors, but it is not popped
from the thread beforehand.  Thus acpi_ds_get_current_walk_state()
called by acpi_ps_parse_aml() subsequently returns it as the new
walk state which is incorrect.

To address this, make acpi_ds_call_control_method() call
acpi_ds_pop_walk_state() to pop next_walk_state from the thread before
returning an error.

Link: https://lore.kernel.org/linux-acpi/20221019073443.248215-1-chenzhongjin@huawei.com/ # [1]
Reported-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Chen Zhongjin &lt;chenzhongjin@huawei.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 404ec60438add1afadaffaed34bb5fe4ddcadd40 ]

A use-after-free in acpi_ps_parse_aml() after a failing invocaion of
acpi_ds_call_control_method() is reported by KASAN [1] and code
inspection reveals that next_walk_state pushed to the thread by
acpi_ds_create_walk_state() is freed on errors, but it is not popped
from the thread beforehand.  Thus acpi_ds_get_current_walk_state()
called by acpi_ps_parse_aml() subsequently returns it as the new
walk state which is incorrect.

To address this, make acpi_ds_call_control_method() call
acpi_ds_pop_walk_state() to pop next_walk_state from the thread before
returning an error.

Link: https://lore.kernel.org/linux-acpi/20221019073443.248215-1-chenzhongjin@huawei.com/ # [1]
Reported-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Chen Zhongjin &lt;chenzhongjin@huawei.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPICA: Fix use-after-free in acpi_ut_copy_ipackage_to_ipackage()</title>
<updated>2023-01-07T11:07:14+00:00</updated>
<author>
<name>Li Zetao</name>
<email>lizetao1@huawei.com</email>
</author>
<published>2022-12-01T08:05:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=133462d35dae95edb944af86b986d4c9dec59bd1'/>
<id>133462d35dae95edb944af86b986d4c9dec59bd1</id>
<content type='text'>
[ Upstream commit 470188b09e92d83c5a997f25f0e8fb8cd2bc3469 ]

There is an use-after-free reported by KASAN:

  BUG: KASAN: use-after-free in acpi_ut_remove_reference+0x3b/0x82
  Read of size 1 at addr ffff888112afc460 by task modprobe/2111
  CPU: 0 PID: 2111 Comm: modprobe Not tainted 6.1.0-rc7-dirty
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
  Call Trace:
   &lt;TASK&gt;
   kasan_report+0xae/0xe0
   acpi_ut_remove_reference+0x3b/0x82
   acpi_ut_copy_iobject_to_iobject+0x3be/0x3d5
   acpi_ds_store_object_to_local+0x15d/0x3a0
   acpi_ex_store+0x78d/0x7fd
   acpi_ex_opcode_1A_1T_1R+0xbe4/0xf9b
   acpi_ps_parse_aml+0x217/0x8d5
   ...
   &lt;/TASK&gt;

The root cause of the problem is that the acpi_operand_object
is freed when acpi_ut_walk_package_tree() fails in
acpi_ut_copy_ipackage_to_ipackage(), lead to repeated release in
acpi_ut_copy_iobject_to_iobject(). The problem was introduced
by "8aa5e56eeb61" commit, this commit is to fix memory leak in
acpi_ut_copy_iobject_to_iobject(), repeatedly adding remove
operation, lead to "acpi_operand_object" used after free.

Fix it by removing acpi_ut_remove_reference() in
acpi_ut_copy_ipackage_to_ipackage(). acpi_ut_copy_ipackage_to_ipackage()
is called to copy an internal package object into another internal
package object, when it fails, the memory of acpi_operand_object
should be freed by the caller.

Fixes: 8aa5e56eeb61 ("ACPICA: Utilities: Fix memory leak in acpi_ut_copy_iobject_to_iobject")
Signed-off-by: Li Zetao &lt;lizetao1@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@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 470188b09e92d83c5a997f25f0e8fb8cd2bc3469 ]

There is an use-after-free reported by KASAN:

  BUG: KASAN: use-after-free in acpi_ut_remove_reference+0x3b/0x82
  Read of size 1 at addr ffff888112afc460 by task modprobe/2111
  CPU: 0 PID: 2111 Comm: modprobe Not tainted 6.1.0-rc7-dirty
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
  Call Trace:
   &lt;TASK&gt;
   kasan_report+0xae/0xe0
   acpi_ut_remove_reference+0x3b/0x82
   acpi_ut_copy_iobject_to_iobject+0x3be/0x3d5
   acpi_ds_store_object_to_local+0x15d/0x3a0
   acpi_ex_store+0x78d/0x7fd
   acpi_ex_opcode_1A_1T_1R+0xbe4/0xf9b
   acpi_ps_parse_aml+0x217/0x8d5
   ...
   &lt;/TASK&gt;

The root cause of the problem is that the acpi_operand_object
is freed when acpi_ut_walk_package_tree() fails in
acpi_ut_copy_ipackage_to_ipackage(), lead to repeated release in
acpi_ut_copy_iobject_to_iobject(). The problem was introduced
by "8aa5e56eeb61" commit, this commit is to fix memory leak in
acpi_ut_copy_iobject_to_iobject(), repeatedly adding remove
operation, lead to "acpi_operand_object" used after free.

Fix it by removing acpi_ut_remove_reference() in
acpi_ut_copy_ipackage_to_ipackage(). acpi_ut_copy_ipackage_to_ipackage()
is called to copy an internal package object into another internal
package object, when it fails, the memory of acpi_operand_object
should be freed by the caller.

Fixes: 8aa5e56eeb61 ("ACPICA: Utilities: Fix memory leak in acpi_ut_copy_iobject_to_iobject")
Signed-off-by: Li Zetao &lt;lizetao1@huawei.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: video: Force backlight native for more TongFang devices</title>
<updated>2022-11-03T14:49:15+00:00</updated>
<author>
<name>Werner Sembach</name>
<email>wse@tuxedocomputers.com</email>
</author>
<published>2022-10-26T15:22:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=819f7dfd046008b826bc386a5357f76fd26c3eb1'/>
<id>819f7dfd046008b826bc386a5357f76fd26c3eb1</id>
<content type='text'>
commit 3dbc80a3e4c55c4a5b89ef207bed7b7de36157b4 upstream.

This commit is very different from the upstream commit! It fixes the same
issue by adding more quirks, rather then the general fix from the 6.1
kernel, because the general fix from the 6.1 kernel is part of a larger
refactoring of the backlight code which is not suitable for the stable
series.

As described in "ACPI: video: Drop NL5x?U, PF4NU1F and PF5?U??
acpi_backlight=native quirks" (10212754a0d2) the upstream commit "ACPI:
video: Make backlight class device registration a separate step (v2)"
(3dbc80a3e4c5) makes these quirks unnecessary. However as mentioned in this
bugtracker ticket https://bugzilla.kernel.org/show_bug.cgi?id=215683#c17
the upstream fix is part of a larger patchset that is overall too complex
for stable.

The TongFang GKxNRxx, GMxNGxx, GMxZGxx, and GMxRGxx / TUXEDO
Stellaris/Polaris Gen 1-4, have the same problem as the Clevo NL5xRU and
NL5xNU / TUXEDO Aura 15 Gen1 and Gen2:
They have a working native and video interface for screen backlight.
However the default detection mechanism first registers the video interface
before unregistering it again and switching to the native interface during
boot. This results in a dangling SBIOS request for backlight change for
some reason, causing the backlight to switch to ~2% once per boot on the
first power cord connect or disconnect event. Setting the native interface
explicitly circumvents this buggy behaviour by avoiding the unregistering
process.

Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3dbc80a3e4c55c4a5b89ef207bed7b7de36157b4 upstream.

This commit is very different from the upstream commit! It fixes the same
issue by adding more quirks, rather then the general fix from the 6.1
kernel, because the general fix from the 6.1 kernel is part of a larger
refactoring of the backlight code which is not suitable for the stable
series.

As described in "ACPI: video: Drop NL5x?U, PF4NU1F and PF5?U??
acpi_backlight=native quirks" (10212754a0d2) the upstream commit "ACPI:
video: Make backlight class device registration a separate step (v2)"
(3dbc80a3e4c5) makes these quirks unnecessary. However as mentioned in this
bugtracker ticket https://bugzilla.kernel.org/show_bug.cgi?id=215683#c17
the upstream fix is part of a larger patchset that is overall too complex
for stable.

The TongFang GKxNRxx, GMxNGxx, GMxZGxx, and GMxRGxx / TUXEDO
Stellaris/Polaris Gen 1-4, have the same problem as the Clevo NL5xRU and
NL5xNU / TUXEDO Aura 15 Gen1 and Gen2:
They have a working native and video interface for screen backlight.
However the default detection mechanism first registers the video interface
before unregistering it again and switching to the native interface during
boot. This results in a dangling SBIOS request for backlight change for
some reason, causing the backlight to switch to ~2% once per boot on the
first power cord connect or disconnect event. Setting the native interface
explicitly circumvents this buggy behaviour by avoiding the unregistering
process.

Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: video: Add Toshiba Satellite/Portege Z830 quirk</title>
<updated>2022-10-26T11:15:45+00:00</updated>
<author>
<name>Arvid Norlander</name>
<email>lkml@vorpal.se</email>
</author>
<published>2022-08-24T18:49:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4f4e3ffff800397b57aae273f3006a3e4011c45b'/>
<id>4f4e3ffff800397b57aae273f3006a3e4011c45b</id>
<content type='text'>
[ Upstream commit 574160b8548deff8b80b174f03201e94ab8431e2 ]

Toshiba Satellite Z830 needs the quirk video_disable_backlight_sysfs_if
for proper backlight control after suspend/resume cycles.

Toshiba Portege Z830 is simply the same laptop rebranded for certain
markets (I looked through the manual to other language sections to confirm
this) and thus also needs this quirk.

Thanks to Hans de Goede for suggesting this fix.

Link: https://www.spinics.net/lists/platform-driver-x86/msg34394.html
Suggested-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Arvid Norlander &lt;lkml@vorpal.se&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Tested-by: Arvid Norlander &lt;lkml@vorpal.se&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@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 574160b8548deff8b80b174f03201e94ab8431e2 ]

Toshiba Satellite Z830 needs the quirk video_disable_backlight_sysfs_if
for proper backlight control after suspend/resume cycles.

Toshiba Portege Z830 is simply the same laptop rebranded for certain
markets (I looked through the manual to other language sections to confirm
this) and thus also needs this quirk.

Thanks to Hans de Goede for suggesting this fix.

Link: https://www.spinics.net/lists/platform-driver-x86/msg34394.html
Suggested-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Arvid Norlander &lt;lkml@vorpal.se&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Tested-by: Arvid Norlander &lt;lkml@vorpal.se&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: video: Shortening quirk list by identifying Clevo by board_name only</title>
<updated>2022-08-25T09:09:22+00:00</updated>
<author>
<name>Werner Sembach</name>
<email>wse@tuxedocomputers.com</email>
</author>
<published>2022-07-07T18:09:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d1793d003955b3ac2f846fcf186fddf265f8e102'/>
<id>d1793d003955b3ac2f846fcf186fddf265f8e102</id>
<content type='text'>
commit f0341e67b3782603737f7788e71bd3530012a4f4 upstream.

Taking a recent change in the i8042 quirklist to this one: Clevo
board_names are somewhat unique, and if not: The generic Board_-/Sys_Vendor
string "Notebook" doesn't help much anyway. So identifying the devices just
by the board_name helps keeping the list significantly shorter and might
even hit more devices requiring the fix.

Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Fixes: c844d22fe0c0 ("ACPI: video: Force backlight native for Clevo NL5xRU and NL5xNU")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f0341e67b3782603737f7788e71bd3530012a4f4 upstream.

Taking a recent change in the i8042 quirklist to this one: Clevo
board_names are somewhat unique, and if not: The generic Board_-/Sys_Vendor
string "Notebook" doesn't help much anyway. So identifying the devices just
by the board_name helps keeping the list significantly shorter and might
even hit more devices requiring the fix.

Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Fixes: c844d22fe0c0 ("ACPI: video: Force backlight native for Clevo NL5xRU and NL5xNU")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: video: Force backlight native for some TongFang devices</title>
<updated>2022-08-25T09:09:22+00:00</updated>
<author>
<name>Werner Sembach</name>
<email>wse@tuxedocomputers.com</email>
</author>
<published>2022-07-07T18:09:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a5ace3271fa811e771df08c07209f6ae47b69254'/>
<id>a5ace3271fa811e771df08c07209f6ae47b69254</id>
<content type='text'>
commit c752089f7cf5b5800c6ace4cdd1a8351ee78a598 upstream.

The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2:
They have a working native and video interface. However the default
detection mechanism first registers the video interface before
unregistering it again and switching to the native interface during boot.
This results in a dangling SBIOS request for backlight change for some
reason, causing the backlight to switch to ~2% once per boot on the first
power cord connect or disconnect event. Setting the native interface
explicitly circumvents this buggy behaviour by avoiding the unregistering
process.

Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c752089f7cf5b5800c6ace4cdd1a8351ee78a598 upstream.

The TongFang PF5PU1G, PF4NU1F, PF5NU1G, and PF5LUXG/TUXEDO BA15 Gen10,
Pulse 14/15 Gen1, and Pulse 15 Gen2 have the same problem as the Clevo
NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2:
They have a working native and video interface. However the default
detection mechanism first registers the video interface before
unregistering it again and switching to the native interface during boot.
This results in a dangling SBIOS request for backlight change for some
reason, causing the backlight to switch to ~2% once per boot on the first
power cord connect or disconnect event. Setting the native interface
explicitly circumvents this buggy behaviour by avoiding the unregistering
process.

Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Reviewed-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Avoid out of bounds access when parsing _CPC data</title>
<updated>2022-04-20T07:06:40+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-03-22T16:02:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3f15609ffa521de12244cd6af24002030dda3f5'/>
<id>b3f15609ffa521de12244cd6af24002030dda3f5</id>
<content type='text'>
commit 40d8abf364bcab23bc715a9221a3c8623956257b upstream.

If the NumEntries field in the _CPC return package is less than 2, do
not attempt to access the "Revision" element of that package, because
it may not be present then.

Fixes: 337aadff8e45 ("ACPI: Introduce CPU performance controls using CPPC")
BugLink: https://lore.kernel.org/lkml/20220322143534.GC32582@xsang-OptiPlex-9020/
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Huang Rui &lt;ray.huang@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 40d8abf364bcab23bc715a9221a3c8623956257b upstream.

If the NumEntries field in the _CPC return package is less than 2, do
not attempt to access the "Revision" element of that package, because
it may not be present then.

Fixes: 337aadff8e45 ("ACPI: Introduce CPU performance controls using CPPC")
BugLink: https://lore.kernel.org/lkml/20220322143534.GC32582@xsang-OptiPlex-9020/
Reported-by: kernel test robot &lt;oliver.sang@intel.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Reviewed-by: Huang Rui &lt;ray.huang@amd.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI/APEI: Limit printable size of BERT table data</title>
<updated>2022-04-20T07:06:38+00:00</updated>
<author>
<name>Darren Hart</name>
<email>darren@os.amperecomputing.com</email>
</author>
<published>2022-03-08T18:50:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3cf5aa240be4782294ab01725a74eab917acfd5f'/>
<id>3cf5aa240be4782294ab01725a74eab917acfd5f</id>
<content type='text'>
[ Upstream commit 3f8dec116210ca649163574ed5f8df1e3b837d07 ]

Platforms with large BERT table data can trigger soft lockup errors
while attempting to print the entire BERT table data to the console at
boot:

  watchdog: BUG: soft lockup - CPU#160 stuck for 23s! [swapper/0:1]

Observed on Ampere Altra systems with a single BERT record of ~250KB.

The original bert driver appears to have assumed relatively small table
data. Since it is impractical to reassemble large table data from
interwoven console messages, and the table data is available in

  /sys/firmware/acpi/tables/data/BERT

limit the size for tables printed to the console to 1024 (for no reason
other than it seemed like a good place to kick off the discussion, would
appreciate feedback from existing users in terms of what size would
maintain their current usage model).

Alternatively, we could make printing a CONFIG option, use the
bert_disable boot arg (or something similar), or use a debug log level.
However, all those solutions require extra steps or change the existing
behavior for small table data. Limiting the size preserves existing
behavior on existing platforms with small table data, and eliminates the
soft lockups for platforms with large table data, while still making it
available.

Signed-off-by: Darren Hart &lt;darren@os.amperecomputing.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@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 3f8dec116210ca649163574ed5f8df1e3b837d07 ]

Platforms with large BERT table data can trigger soft lockup errors
while attempting to print the entire BERT table data to the console at
boot:

  watchdog: BUG: soft lockup - CPU#160 stuck for 23s! [swapper/0:1]

Observed on Ampere Altra systems with a single BERT record of ~250KB.

The original bert driver appears to have assumed relatively small table
data. Since it is impractical to reassemble large table data from
interwoven console messages, and the table data is available in

  /sys/firmware/acpi/tables/data/BERT

limit the size for tables printed to the console to 1024 (for no reason
other than it seemed like a good place to kick off the discussion, would
appreciate feedback from existing users in terms of what size would
maintain their current usage model).

Alternatively, we could make printing a CONFIG option, use the
bert_disable boot arg (or something similar), or use a debug log level.
However, all those solutions require extra steps or change the existing
behavior for small table data. Limiting the size preserves existing
behavior on existing platforms with small table data, and eliminates the
soft lockups for platforms with large table data, while still making it
available.

Signed-off-by: Darren Hart &lt;darren@os.amperecomputing.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPICA: Avoid walking the ACPI Namespace if it is not there</title>
<updated>2022-04-20T07:06:38+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2022-03-07T19:28:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b98f467dad37bd4acc3076bcfb27d153b079c4bc'/>
<id>b98f467dad37bd4acc3076bcfb27d153b079c4bc</id>
<content type='text'>
[ Upstream commit 0c9992315e738e7d6e927ef36839a466b080dba6 ]

ACPICA commit b1c3656ef4950098e530be68d4b589584f06cddc

Prevent acpi_ns_walk_namespace() from crashing when called with
start_node equal to ACPI_ROOT_OBJECT if the Namespace has not been
instantiated yet and acpi_gbl_root_node is NULL.

For instance, this can happen if the kernel is run with "acpi=off"
in the command line.

Link: https://github.com/acpica/acpica/commit/b1c3656ef4950098e530be68d4b589584f06cddc
Link: https://lore.kernel.org/linux-acpi/CAJZ5v0hJWW_vZ3wwajE7xT38aWjY7cZyvqMJpXHzUL98-SiCVQ@mail.gmail.com/
Reported-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@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 0c9992315e738e7d6e927ef36839a466b080dba6 ]

ACPICA commit b1c3656ef4950098e530be68d4b589584f06cddc

Prevent acpi_ns_walk_namespace() from crashing when called with
start_node equal to ACPI_ROOT_OBJECT if the Namespace has not been
instantiated yet and acpi_gbl_root_node is NULL.

For instance, this can happen if the kernel is run with "acpi=off"
in the command line.

Link: https://github.com/acpica/acpica/commit/b1c3656ef4950098e530be68d4b589584f06cddc
Link: https://lore.kernel.org/linux-acpi/CAJZ5v0hJWW_vZ3wwajE7xT38aWjY7cZyvqMJpXHzUL98-SiCVQ@mail.gmail.com/
Reported-by: Hans de Goede &lt;hdegoede@redhat.com&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: video: Force backlight native for Clevo NL5xRU and NL5xNU</title>
<updated>2022-03-28T06:06:06+00:00</updated>
<author>
<name>Werner Sembach</name>
<email>wse@tuxedocomputers.com</email>
</author>
<published>2022-03-15T19:02:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f7735356dc3e25fad21d248acd703ee40ca37483'/>
<id>f7735356dc3e25fad21d248acd703ee40ca37483</id>
<content type='text'>
commit c844d22fe0c0b37dc809adbdde6ceb6462c43acf upstream.

Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a working
native and video interface. However the default detection mechanism first
registers the video interface before unregistering it again and switching
to the native interface during boot. This results in a dangling SBIOS
request for backlight change for some reason, causing the backlight to
switch to ~2% once per boot on the first power cord connect or disconnect
event. Setting the native interface explicitly circumvents this buggy
behaviour by avoiding the unregistering process.

Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c844d22fe0c0b37dc809adbdde6ceb6462c43acf upstream.

Clevo NL5xRU and NL5xNU/TUXEDO Aura 15 Gen1 and Gen2 have both a working
native and video interface. However the default detection mechanism first
registers the video interface before unregistering it again and switching
to the native interface during boot. This results in a dangling SBIOS
request for backlight change for some reason, causing the backlight to
switch to ~2% once per boot on the first power cord connect or disconnect
event. Setting the native interface explicitly circumvents this buggy
behaviour by avoiding the unregistering process.

Signed-off-by: Werner Sembach &lt;wse@tuxedocomputers.com&gt;
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
