<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/acpi, branch v7.0.9</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>ACPI: video: force native backlight on HP OMEN 16 (8A44)</title>
<updated>2026-05-14T13:31:02+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.tavy.me/linux-stable.git/commit/?id=90e55eb44e8a681e51407b7c915875f1f91cba2a'/>
<id>90e55eb44e8a681e51407b7c915875f1f91cba2a</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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: CPPC: Fix related_cpus inconsistency during CPU hotplug</title>
<updated>2026-05-14T13:31:02+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.tavy.me/linux-stable.git/commit/?id=43caab025a48f2a2da6e2d21e0f2add688306b8c'/>
<id>43caab025a48f2a2da6e2d21e0f2add688306b8c</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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: video: Add backlight=native quirk for Dell OptiPlex 7770 AIO</title>
<updated>2026-05-14T13:31:02+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.tavy.me/linux-stable.git/commit/?id=5ff8cea1915274ab831173dc450d717f2a1b33ef'/>
<id>5ff8cea1915274ab831173dc450d717f2a1b33ef</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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: scan: Use acpi_dev_put() in object add error paths</title>
<updated>2026-05-14T13:31:02+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.tavy.me/linux-stable.git/commit/?id=68eb9d1b3f53e9d8fd4805f293f00e7c3808ce60'/>
<id>68eb9d1b3f53e9d8fd4805f293f00e7c3808ce60</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>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: arm64: cpuidle: Tolerate platforms with no deep PSCI idle states</title>
<updated>2026-05-14T13:31:02+00:00</updated>
<author>
<name>Breno Leitao</name>
<email>leitao@debian.org</email>
</author>
<published>2026-04-20T09:27:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=77c5cb8da7b792c84a32d44867d3838b71024515'/>
<id>77c5cb8da7b792c84a32d44867d3838b71024515</id>
<content type='text'>
commit 3ea4415015d690a51a3fb1f98dfc9a02f88f7bc4 upstream.

Commit cac173bea57d ("ACPI: processor: idle: Rework the handling of
acpi_processor_ffh_lpi_probe()") moved the acpi_processor_ffh_lpi_probe()
call from acpi_processor_setup_cpuidle_dev(), where its return value was
ignored, to acpi_processor_get_power_info(), where it is now treated as
a hard failure. As a result, platforms where psci_acpi_cpu_init_idle()
returned -ENODEV stopped registering any cpuidle states, forcing CPUs to
busy-poll when idle.

On NVIDIA Grace (aarch64) systems with PSCIv1.1, pr-&gt;power.count is 1
(only WFI, no deep PSCI states beyond it), so the previous
"count = pr-&gt;power.count - 1; if (count &lt;= 0) return -ENODEV;" check
returned -ENODEV for all 72 CPUs and disabled cpuidle entirely.

The lpi_states count is already validated in acpi_processor_get_lpi_info(),
so the check here is redundant. Simplify the loop to iterate over
lpi_states[1..power.count). When only WFI is present, the loop body
simply does not execute and the function returns 0, which is the correct
outcome: there is nothing to validate for FFH and no error to report.

Suggested-by: Huisong Li &lt;lihuisong@huawei.com&gt;
Cc: stable@vger.kernel.org
Fixes: cac173bea57d ("ACPI: processor: idle: Rework the handling of acpi_processor_ffh_lpi_probe()")
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@kernel.org&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.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 3ea4415015d690a51a3fb1f98dfc9a02f88f7bc4 upstream.

Commit cac173bea57d ("ACPI: processor: idle: Rework the handling of
acpi_processor_ffh_lpi_probe()") moved the acpi_processor_ffh_lpi_probe()
call from acpi_processor_setup_cpuidle_dev(), where its return value was
ignored, to acpi_processor_get_power_info(), where it is now treated as
a hard failure. As a result, platforms where psci_acpi_cpu_init_idle()
returned -ENODEV stopped registering any cpuidle states, forcing CPUs to
busy-poll when idle.

On NVIDIA Grace (aarch64) systems with PSCIv1.1, pr-&gt;power.count is 1
(only WFI, no deep PSCI states beyond it), so the previous
"count = pr-&gt;power.count - 1; if (count &lt;= 0) return -ENODEV;" check
returned -ENODEV for all 72 CPUs and disabled cpuidle entirely.

The lpi_states count is already validated in acpi_processor_get_lpi_info(),
so the check here is redundant. Simplify the loop to iterate over
lpi_states[1..power.count). When only WFI is present, the loop body
simply does not execute and the function returns 0, which is the correct
outcome: there is nothing to validate for FFH and no error to report.

Suggested-by: Huisong Li &lt;lihuisong@huawei.com&gt;
Cc: stable@vger.kernel.org
Fixes: cac173bea57d ("ACPI: processor: idle: Rework the handling of acpi_processor_ffh_lpi_probe()")
Signed-off-by: Breno Leitao &lt;leitao@debian.org&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@kernel.org&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'riscv-for-linus-7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux</title>
<updated>2026-04-05T21:43:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2026-04-05T21:43:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=85fb6da43ac58dc7d1a6242e7b2102fd1d4954bc'/>
<id>85fb6da43ac58dc7d1a6242e7b2102fd1d4954bc</id>
<content type='text'>
Pull RISC-V fixes from Paul Walmsley:

 - Fix a CONFIG_SPARSEMEM crash on RV32 by avoiding early phys_to_page()

 - Prevent runtime const infrastructure from being used by modules,
   similar to what was done for x86

 - Avoid problems when shutting down ACPI systems with IOMMUs by adding
   a device dependency between IOMMU and devices that use it

 - Fix a bug where the CPU pointer masking state isn't properly reset
   when tagged addresses aren't enabled for a task

 - Fix some incorrect register assignments, and add some missing ones,
   in kgdb support code

 - Fix compilation of non-kernel code that uses the ptrace uapi header
   by replacing BIT() with _BITUL()

 - Fix compilation of the validate_v_ptrace kselftest by working around
   kselftest macro expansion issues

* tag 'riscv-for-linus-7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  ACPI: RIMT: Add dependency between iommu and devices
  selftests: riscv: Add braces around EXPECT_EQ()
  riscv: use _BITUL macro rather than BIT() in ptrace uapi and kselftests
  riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set
  riscv: make runtime const not usable by modules
  riscv: patch: Avoid early phys_to_page()
  riscv: kgdb: fix several debug register assignment bugs
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull RISC-V fixes from Paul Walmsley:

 - Fix a CONFIG_SPARSEMEM crash on RV32 by avoiding early phys_to_page()

 - Prevent runtime const infrastructure from being used by modules,
   similar to what was done for x86

 - Avoid problems when shutting down ACPI systems with IOMMUs by adding
   a device dependency between IOMMU and devices that use it

 - Fix a bug where the CPU pointer masking state isn't properly reset
   when tagged addresses aren't enabled for a task

 - Fix some incorrect register assignments, and add some missing ones,
   in kgdb support code

 - Fix compilation of non-kernel code that uses the ptrace uapi header
   by replacing BIT() with _BITUL()

 - Fix compilation of the validate_v_ptrace kselftest by working around
   kselftest macro expansion issues

* tag 'riscv-for-linus-7.0-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  ACPI: RIMT: Add dependency between iommu and devices
  selftests: riscv: Add braces around EXPECT_EQ()
  riscv: use _BITUL macro rather than BIT() in ptrace uapi and kselftests
  riscv: Reset pmm when PR_TAGGED_ADDR_ENABLE is not set
  riscv: make runtime const not usable by modules
  riscv: patch: Avoid early phys_to_page()
  riscv: kgdb: fix several debug register assignment bugs
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: RIMT: Add dependency between iommu and devices</title>
<updated>2026-04-05T00:38:03+00:00</updated>
<author>
<name>Sunil V L</name>
<email>sunilvl@oss.qualcomm.com</email>
</author>
<published>2026-03-03T06:16:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9156585280f161fc1c3552cf1860559edb2bb7e3'/>
<id>9156585280f161fc1c3552cf1860559edb2bb7e3</id>
<content type='text'>
EPROBE_DEFER ensures IOMMU devices are probed before the devices that
depend on them. During shutdown, however, the IOMMU may be removed
first, leading to issues. To avoid this, a device link is added
which enforces the correct removal order.

Fixes: 8f7729552582 ("ACPI: RISC-V: Add support for RIMT")
Signed-off-by: Sunil V L &lt;sunilvl@oss.qualcomm.com&gt;
Link: https://patch.msgid.link/20260303061605.722949-1-sunilvl@oss.qualcomm.com
Signed-off-by: Paul Walmsley &lt;pjw@kernel.org&gt;</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
EPROBE_DEFER ensures IOMMU devices are probed before the devices that
depend on them. During shutdown, however, the IOMMU may be removed
first, leading to issues. To avoid this, a device link is added
which enforces the correct removal order.

Fixes: 8f7729552582 ("ACPI: RISC-V: Add support for RIMT")
Signed-off-by: Sunil V L &lt;sunilvl@oss.qualcomm.com&gt;
Link: https://patch.msgid.link/20260303061605.722949-1-sunilvl@oss.qualcomm.com
Signed-off-by: Paul Walmsley &lt;pjw@kernel.org&gt;</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: EC: clean up handlers on probe failure in acpi_ec_setup()</title>
<updated>2026-03-24T17:47:10+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.tavy.me/linux-stable.git/commit/?id=f6484cadbcaf26b5844b51bd7307a663dda48ef6'/>
<id>f6484cadbcaf26b5844b51bd7307a663dda48ef6</id>
<content type='text'>
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;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'acpica' and 'acpi-bus'</title>
<updated>2026-03-19T13:57:06+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2026-03-19T13:57:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5cbcd6c0742a2986782a9e2c92aa250d8f5c137d'/>
<id>5cbcd6c0742a2986782a9e2c92aa250d8f5c137d</id>
<content type='text'>
Merge an ACPICA fix and a core ACPI support code fix for 7.0-rc5:

 - Update the format of the last argument of _DSM to avoid printing
   confusing error messages in some cases (Saket Dumbre)

 - Fix MFD child automatic modprobe issue by removing a stale check
   from acpi_companion_match() (Pratap Nirujogi)

* acpica:
  ACPICA: Update the format of Arg3 of _DSM

* acpi-bus:
  ACPI: bus: Fix MFD child automatic modprobe issue
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge an ACPICA fix and a core ACPI support code fix for 7.0-rc5:

 - Update the format of the last argument of _DSM to avoid printing
   confusing error messages in some cases (Saket Dumbre)

 - Fix MFD child automatic modprobe issue by removing a stale check
   from acpi_companion_match() (Pratap Nirujogi)

* acpica:
  ACPICA: Update the format of Arg3 of _DSM

* acpi-bus:
  ACPI: bus: Fix MFD child automatic modprobe issue
</pre>
</div>
</content>
</entry>
<entry>
<title>ACPI: bus: Fix MFD child automatic modprobe issue</title>
<updated>2026-03-18T10:57:22+00:00</updated>
<author>
<name>Pratap Nirujogi</name>
<email>pratap.nirujogi@amd.com</email>
</author>
<published>2026-03-18T03:47:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e7648ffecb7fcb7400e123bb6ea989633a104fc3'/>
<id>e7648ffecb7fcb7400e123bb6ea989633a104fc3</id>
<content type='text'>
MFD child devices sharing parent's ACPI Companion fails to probe as
acpi_companion_match() returns incompatible ACPI Companion handle for
binding with the check for pnp.type.backlight added recently. Remove this
pnp.type.backlight check in acpi_companion_match() to fix the automatic
modprobe issue.

Fixes: 7a7a7ed5f8bdb ("ACPI: scan: Register platform devices for backlight device objects")
Signed-off-by: Pratap Nirujogi &lt;pratap.nirujogi@amd.com&gt;
Link: https://patch.msgid.link/20260318034842.1216536-1-pratap.nirujogi@amd.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
MFD child devices sharing parent's ACPI Companion fails to probe as
acpi_companion_match() returns incompatible ACPI Companion handle for
binding with the check for pnp.type.backlight added recently. Remove this
pnp.type.backlight check in acpi_companion_match() to fix the automatic
modprobe issue.

Fixes: 7a7a7ed5f8bdb ("ACPI: scan: Register platform devices for backlight device objects")
Signed-off-by: Pratap Nirujogi &lt;pratap.nirujogi@amd.com&gt;
Link: https://patch.msgid.link/20260318034842.1216536-1-pratap.nirujogi@amd.com
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
