<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/drivers/acpi, branch v6.12.92</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v6.12.92</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v6.12.92'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2026-05-23T11:04:23+00:00</updated>
<entry>
<title>ACPI: AGDI: fix missing newline in error message</title>
<updated>2026-05-23T11:04:23+00:00</updated>
<author>
<name>Haoyu Lu</name>
<email>hechushiguitu666@gmail.com</email>
</author>
<published>2026-04-07T03:31:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a67cfe3c8b9739888ff4dfa89ffce718ab5d9b5e'/>
<id>urn:sha1:a67cfe3c8b9739888ff4dfa89ffce718ab5d9b5e</id>
<content type='text'>
[ Upstream commit b178330b67abb7293b6de28b2a49d49c83962db5 ]

Add the missing trailing newline to the dev_err() message
printed when SDEI event registration fails.

This keeps the error output as a properly terminated log line.

Fixes: a2a591fb76e6 ("ACPI: AGDI: Add driver for Arm Generic Diagnostic Dump and Reset device")
Reviewed-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Signed-off-by: Haoyu Lu &lt;hechushiguitu666@gmail.com&gt;
Reviewed-by: Hanjun Guo &lt;guohanjun@huawei.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ACPI: x86: cmos_rtc: Improve coordination with ACPI TAD driver</title>
<updated>2026-05-23T11:04:20+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2026-02-23T15:28:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=42ac969667ba1d159e1fa24b366b81a6ea40d4e0'/>
<id>urn:sha1:42ac969667ba1d159e1fa24b366b81a6ea40d4e0</id>
<content type='text'>
[ Upstream commit 6cee29ad9d7e400d39ae0b1a54447fedcb62eecd ]

If a CMOS RTC (PNP0B00/PNP0B01/PNP0B02) device coexists with an ACPI
TAD (timer and event alarm device, ACPI000E), the ACPI TAD driver will
attempt to install the CMOS RTC address space hanlder that has been
installed already and the TAD probing will fail.

Avoid that by changing acpi_install_cmos_rtc_space_handler() to return
zero and acpi_remove_cmos_rtc_space_handler() to do nothing if the CMOS
RTC address space handler has been installed already.

Fixes: 596ca52a56da ("ACPI: TAD: Install SystemCMOS address space handler for ACPI000E")
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/2415111.ElGaqSPkdT@rafael.j.wysocki
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ACPI: x86: cmos_rtc: Clean up address space handler driver</title>
<updated>2026-05-23T11:04:20+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2026-02-23T15:28:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=a92995c3d03bc42375b08f41614e21ae2effce5f'/>
<id>urn:sha1:a92995c3d03bc42375b08f41614e21ae2effce5f</id>
<content type='text'>
[ Upstream commit ba0b236736dde4059bdcb8e99beaa50d6e5b6e7e ]

Make multiple changes that do not alter functionality to the CMOS RTC
ACPI address space handler driver, including the following:

 - Drop the unused .detach() callback from cmos_rtc_handler.

 - Rename acpi_cmos_rtc_attach_handler() to acpi_cmos_rtc_attach().

 - Rearrange acpi_cmos_rtc_space_handler() to reduce the number of
   redundant checks and make white space follow the coding style.

 - Adjust an error message in acpi_install_cmos_rtc_space_handler()
   and make the white space follow the coding style.

 - Rearrange acpi_remove_cmos_rtc_space_handler() and adjust an error
   message in it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/5094429.31r3eYUQgx@rafael.j.wysocki
Stable-dep-of: 6cee29ad9d7e ("ACPI: x86: cmos_rtc: Improve coordination with ACPI TAD driver")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ACPI: video: force native backlight on HP OMEN 16 (8A44)</title>
<updated>2026-05-14T13:29:17+00:00</updated>
<author>
<name>Shivam Kalra</name>
<email>shivamkalra98@zohomail.in</email>
</author>
<published>2026-04-26T14:08:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5b8d6a94f2e2cc501e2a91af2f0cf62995c2894a'/>
<id>urn:sha1:5b8d6a94f2e2cc501e2a91af2f0cf62995c2894a</id>
<content type='text'>
commit 4b506ea5351a1f5937ac632a4a5c35f6f796cc41 upstream.

The HP OMEN 16 Gaming Laptop (board name 8A44) has a mux-less hybrid
GPU configuration with AMD Rembrandt (Radeon 680M) and NVIDIA GA104
(RTX 3070 Ti). The internal eDP panel is wired to the AMD iGPU.

When Nouveau loads without GSP firmware, the ACPI video backlight
device (acpi_video0) gets registered alongside the native AMD
backlight (amdgpu_bl2). In this state, writes to amdgpu_bl2 update
the software brightness value but fail to change the physical panel
brightness.

Force native backlight to prevent acpi_video0 from registering.
Confirmed that booting with acpi_backlight=native resolves the
issue.

Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Shivam Kalra &lt;shivamkalra98@zohomail.in&gt;
Link: https://patch.msgid.link/20260426-omen-16-backlight-fix-v1-1-62364f268ea6@zohomail.in
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>
</entry>
<entry>
<title>ACPI: CPPC: Fix related_cpus inconsistency during CPU hotplug</title>
<updated>2026-05-14T13:29:17+00:00</updated>
<author>
<name>Jinjie Ruan</name>
<email>ruanjinjie@huawei.com</email>
</author>
<published>2026-04-17T04:01:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8c18175a871d0434a4ed216dcfd88974f0eb78b6'/>
<id>urn:sha1:8c18175a871d0434a4ed216dcfd88974f0eb78b6</id>
<content type='text'>
commit 75141a770f4f8225d316f6c7e146723a32e9720e upstream.

When concurrently bringing up and down two SMT threads of a physical
core, many warning call traces occur as below:

The issue timeline is as follows:

 1. When the system starts,
    cpufreq: CPU: 220, policy-&gt;related_cpus: 220-221, policy-&gt;cpus: 220-221

 2. Offline CPU 220 and CPU 221.

 3. Online CPU 220
    - CPU 221 is now offline, as acpi_get_psd_map() use
      for_each_online_cpu(), so the cpu_data-&gt;shared_cpu_map,
      policy-&gt;cpus, and related_cpus has only CPU 220.

    cpufreq: CPU: 220, policy-&gt;related_cpus: 220, policy-&gt;cpus: 220

 4. Offline CPU 220

 5. Online CPU 221, the below call trace occurs:
    - Since CPU 220 and CPU 221 share one policy, and
      policy-&gt;related_cpus = 220 after step 3, so CPU 221
      is not in policy-&gt;related_cpus but
      per_cpu(cpufreq_cpu_data, cpu221) is not NULL.

After reverting commit 56eb0c0ed345 ("ACPI: CPPC: Fix remaining
for_each_possible_cpu() to use online CPUs"), the issue disappeared.

The _PSD (P-State Dependency) defines the hardware-level dependency of
frequency control across CPU cores. Since this relationship is a physical
attribute of the hardware topology, it remains constant regardless of the
online or offline status of the CPUs.

Using for_each_online_cpu() in acpi_get_psd_map() is problematic. If a
CPU is offline, it will be excluded from the shared_cpu_map.
Consequently, if that CPU is brought online later, the kernel will fail
to recognize it as part of any shared frequency domain.

Switch back to for_each_possible_cpu() to ensure that all cores defined
in the ACPI tables are correctly mapped into their respective performance
domains from the start. This aligns with the logic of policy-&gt;related_cpus,
which must encompass all potentially available cores in the domain to
prevent logic gaps during CPU hotplug operations.

To resolve the original issue regarding the "nosmt" or "nosmt=force"
boot parameter, as send_pcc_cmd() function already does if (!desc)
continue, so reverting that loop back to for_each_possible_cpu() is ok,
only need to change the match_cpc_ptr NULL case in acpi_get_psd_map() to
continue as Sean suggested.

How to reproduce, on arm64 machine with SMT support which use acpi cppc
cpufreq driver:

	bash test.sh 220 &amp; bash test.sh 221 &amp;

	The test.sh is as below:
		while true
			do
			echo 0 &gt; /sys/devices/system/cpu/cpu${1}/online
			sleep 0.5
			cat /sys/devices/system/cpu/cpu${1}/cpufreq/related_cpus
			echo 1 &gt;  /sys/devices/system/cpu/cpu${1}/online
			cat /sys/devices/system/cpu/cpu${1}/cpufreq/related_cpus
		done

	CPU: 221 PID: 1119 Comm: cpuhp/221 Kdump: loaded Not tainted 6.6.0debug+ #5
	Hardware name: To be filled by O.E.M. S920X20/BC83AMDA01-7270Z, BIOS 20.39 09/04/2024
	pstate: a1400009 (NzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
	pc : cpufreq_online+0x8ac/0xa90
	lr : cpuhp_cpufreq_online+0x18/0x30
	sp : ffff80008739bce0
	x29: ffff80008739bce0 x28: 0000000000000000 x27: ffff28400ca32200
	x26: 0000000000000000 x25: 0000000000000003 x24: ffffd483503ff000
	x23: ffffd483504051a0 x22: ffffd48350024a00 x21: 00000000000000dd
	x20: 000000000000001d x19: ffff28400ca32000 x18: 0000000000000000
	x17: 0000000000000020 x16: ffffd4834e6a3fc8 x15: 0000000000000020
	x14: 0000000000000008 x13: 0000000000000001 x12: 00000000ffffffff
	x11: 0000000000000040 x10: ffffd48350430728 x9 : ffffd4834f087c78
	x8 : 0000000000000001 x7 : ffff2840092bdf00 x6 : ffffd483504264f0
	x5 : ffffd48350405000 x4 : ffff283f7f95cc60 x3 : 0000000000000000
	x2 : ffff53bc2f94b000 x1 : 00000000000000dd x0 : 0000000000000000
	Call trace:
	 cpufreq_online+0x8ac/0xa90
	 cpuhp_cpufreq_online+0x18/0x30
	 cpuhp_invoke_callback+0x128/0x580
	 cpuhp_thread_fun+0x110/0x1b0
	 smpboot_thread_fn+0x140/0x190
	 kthread+0xec/0x100
	 ret_from_fork+0x10/0x20
	---[ end trace 0000000000000000 ]---

Cc: All applicable &lt;stable@vger.kernel.org&gt;
Fixes: 56eb0c0ed345 ("ACPI: CPPC: Fix remaining for_each_possible_cpu() to use online CPUs")
Co-developed-by: Sean Kelley &lt;skelley@nvidia.com&gt;
Signed-off-by: Sean Kelley &lt;skelley@nvidia.com&gt;
Signed-off-by: Jinjie Ruan &lt;ruanjinjie@huawei.com&gt;
[ rjw: Changelog edits ]
Link: https://patch.msgid.link/20260417040112.3727756-1-ruanjinjie@huawei.com
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>
</entry>
<entry>
<title>ACPI: video: Add backlight=native quirk for Dell OptiPlex 7770 AIO</title>
<updated>2026-05-14T13:29:17+00:00</updated>
<author>
<name>Jan Schär</name>
<email>jan@jschaer.ch</email>
</author>
<published>2026-04-11T09:26:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=ad766e7f32e2822ce1e9998809a3dcc8b9184e37'/>
<id>urn:sha1:ad766e7f32e2822ce1e9998809a3dcc8b9184e37</id>
<content type='text'>
commit ad7997f5a01af6f711fe6b6a2df578b964109d49 upstream.

The Dell OptiPlex 7770 AIO needs the same quirk as the 7760 AIO. The
backlight can be controlled with the native controller, intel_backlight,
but not with dell_uart_backlight.

I dumped the DSDT using acpidump, acpixtract and iasl, and confirmed
that it contains the DELL0501 device. When loading the
dell_uart_backlight driver with `rmmod dell_uart_backlight`, `modprobe
dell_uart_backlight dyndbg`, it reports "Firmware version: GL_Re_V18".

Fixes: cd8e468efb4f ("ACPI: video: Add Dell UART backlight controller detection")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Jan Schär &lt;jan@jschaer.ch&gt;
Reviewed-by: Hans de Goede &lt;johannes.goede@oss.qualcomm.com&gt;
Link: https://patch.msgid.link/20260411092606.47925-1-jan@jschaer.ch
Signed-off-by: Rafael J. Wysocki &lt;rjw@rjwysocki.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ACPI: scan: Use acpi_dev_put() in object add error paths</title>
<updated>2026-05-14T13:29:17+00:00</updated>
<author>
<name>Guangshuo Li</name>
<email>lgs201920130244@gmail.com</email>
</author>
<published>2026-04-13T13:53:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=7ef8e29d9012686434948d1a928a9777091948f5'/>
<id>urn:sha1:7ef8e29d9012686434948d1a928a9777091948f5</id>
<content type='text'>
commit 9c0acc169ac71535477caedea8315f7041c5f07c upstream.

After acpi_init_device_object(), the lifetime of struct acpi_device is
managed by the driver core through reference counting.

Both acpi_add_power_resource() and acpi_add_single_object() call
acpi_init_device_object() and then invoke acpi_device_add(). If that
fails, their error paths call the release callback directly instead of
dropping the device reference through acpi_dev_put().

This bypasses the normal device lifetime rules and frees the object
without releasing the reference acquired by device_initialize(), which
may lead to a refcount leak.

The issue was identified by a static analysis tool I developed and
confirmed by manual review.

Fix both error paths by using acpi_dev_put() and let the release
callback handle the final cleanup.

Fixes: 781d737c7466 ("ACPI: Drop power resources driver")
Fixes: 718fb0de8ff88 ("ACPI: fix NULL bug for HID/UID string")
Cc: All applicable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Guangshuo Li &lt;lgs201920130244@gmail.com&gt;
Link: https://patch.msgid.link/20260413135343.2884481-1-lgs201920130244@gmail.com
Signed-off-by: Rafael J. Wysocki &lt;rjw@rjwysocki.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()</title>
<updated>2026-04-02T11:09:40+00:00</updated>
<author>
<name>Weiming Shi</name>
<email>bestswngs@gmail.com</email>
</author>
<published>2026-03-24T16:54:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=808c0f156f48d5b8ca34088cbbfba8444e606cbc'/>
<id>urn:sha1:808c0f156f48d5b8ca34088cbbfba8444e606cbc</id>
<content type='text'>
[ Upstream commit f6484cadbcaf26b5844b51bd7307a663dda48ef6 ]

When ec_install_handlers() returns -EPROBE_DEFER on reduced-hardware
platforms, it has already started the EC and installed the address
space handler with the struct acpi_ec pointer as handler context.
However, acpi_ec_setup() propagates the error without any cleanup.

The caller acpi_ec_add() then frees the struct acpi_ec for non-boot
instances, leaving a dangling handler context in ACPICA.

Any subsequent AML evaluation that accesses an EC OpRegion field
dispatches into acpi_ec_space_handler() with the freed pointer,
causing a use-after-free:

 BUG: KASAN: slab-use-after-free in mutex_lock (kernel/locking/mutex.c:289)
 Write of size 8 at addr ffff88800721de38 by task init/1
 Call Trace:
  &lt;TASK&gt;
  mutex_lock (kernel/locking/mutex.c:289)
  acpi_ec_space_handler (drivers/acpi/ec.c:1362)
  acpi_ev_address_space_dispatch (drivers/acpi/acpica/evregion.c:293)
  acpi_ex_access_region (drivers/acpi/acpica/exfldio.c:246)
  acpi_ex_field_datum_io (drivers/acpi/acpica/exfldio.c:509)
  acpi_ex_extract_from_field (drivers/acpi/acpica/exfldio.c:700)
  acpi_ex_read_data_from_field (drivers/acpi/acpica/exfield.c:327)
  acpi_ex_resolve_node_to_value (drivers/acpi/acpica/exresolv.c:392)
  &lt;/TASK&gt;

 Allocated by task 1:
  acpi_ec_alloc (drivers/acpi/ec.c:1424)
  acpi_ec_add (drivers/acpi/ec.c:1692)

 Freed by task 1:
  kfree (mm/slub.c:6876)
  acpi_ec_add (drivers/acpi/ec.c:1751)

The bug triggers on reduced-hardware EC platforms (ec-&gt;gpe &lt; 0)
when the GPIO IRQ provider defers probing. Once the stale handler
exists, any unprivileged sysfs read that causes AML to touch an
EC OpRegion (battery, thermal, backlight) exercises the dangling
pointer.

Fix this by calling ec_remove_handlers() in the error path of
acpi_ec_setup() before clearing first_ec. ec_remove_handlers()
checks each EC_FLAGS_* bit before acting, so it is safe to call
regardless of how far ec_install_handlers() progressed:

  -ENODEV  (handler not installed): only calls acpi_ec_stop()
  -EPROBE_DEFER (handler installed): removes handler, stops EC

Fixes: 03e9a0e05739 ("ACPI: EC: Consolidate event handler installation code")
Reported-by: Xiang Mei &lt;xmei5@asu.edu&gt;
Signed-off-by: Weiming Shi &lt;bestswngs@gmail.com&gt;
Link: https://patch.msgid.link/20260324165458.1337233-2-bestswngs@gmail.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ACPI: processor: Fix previous acpi_processor_errata_piix4() fix</title>
<updated>2026-03-25T10:08:54+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2026-03-17T20:39:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=e0c470049344e9346fff79d7e2362212c216665e'/>
<id>urn:sha1:e0c470049344e9346fff79d7e2362212c216665e</id>
<content type='text'>
[ Upstream commit bf504b229cb8d534eccbaeaa23eba34c05131e25 ]

After commi f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference
in acpi_processor_errata_piix4()"), device pointers may be dereferenced
after dropping references to the device objects pointed to by them,
which may cause a use-after-free to occur.

Moreover, debug messages about enabling the errata may be printed
if the errata flags corresponding to them are unset.

Address all of these issues by moving message printing to the points
in the code where the errata flags are set.

Fixes: f132e089fe89 ("ACPI: processor: Fix NULL-pointer dereference in acpi_processor_errata_piix4()")
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Closes: https://lore.kernel.org/linux-acpi/938e2206-def5-4b7a-9b2c-d1fd37681d8a@roeck-us.net/
Reviewed-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Link: https://patch.msgid.link/5975693.DvuYhMxLoT@rafael.j.wysocki
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>ACPI: OSL: fix __iomem type on return from acpi_os_map_generic_address()</title>
<updated>2026-03-25T10:08:30+00:00</updated>
<author>
<name>Ben Dooks</name>
<email>ben.dooks@codethink.co.uk</email>
</author>
<published>2026-03-11T10:58:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=2ca9da563a5fca293b0218e3ae9fc83226cacedd'/>
<id>urn:sha1:2ca9da563a5fca293b0218e3ae9fc83226cacedd</id>
<content type='text'>
[ Upstream commit 393815f57651101f1590632092986d1d5a3a41bd ]

The pointer returned from acpi_os_map_generic_address() is
tagged with __iomem, so make the rv it is returned to also
of void __iomem * type.

Fixes the following sparse warning:

drivers/acpi/osl.c:1686:20: warning: incorrect type in assignment (different address spaces)
drivers/acpi/osl.c:1686:20:    expected void *rv
drivers/acpi/osl.c:1686:20:    got void [noderef] __iomem *

Fixes: 6915564dc5a8 ("ACPI: OSL: Change the type of acpi_os_map_generic_address() return value")
Signed-off-by: Ben Dooks &lt;ben.dooks@codethink.co.uk&gt;
[ rjw: Subject tweak, added Fixes tag ]
Link: https://patch.msgid.link/20260311105835.463030-1-ben.dooks@codethink.co.uk
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
