Commit 4df4d2a577db for kernel
commit 4df4d2a577db2d3d57b888bcfb1206fc74661d16
Merge: ccc4d9f8912a 84c4409e8566
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date: Wed Oct 21 12:08:18 2026 -1000
Merge tag 'acpi-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI support updates from Rafael Wysocki:
"The most significant change here is the rework of the core ACPI device
enumeration code to avoid initializing ACPI power management
prematurely for devices with unmet dependencies. This essentially is a
problem fix, but it requires taking PCI device enumeration ordering
into account among other things, so it is far from straightforward.
There was an attempt to do this in the 7.3 time frame that had to be
reverted, so this time it is done much more carefully.
There is also an ACPI thermal control update rearranging the code to
register thermal class cooling devices under specific parents, which
is visible in sysfs. This helps to figure out what is represented by
those devices much more easily, but it also allows the binding of
cooling devices to trip points in thermal zones to be adjusted so it
need not rely on specific cooling device data usage in thermal
drivers.
From the number of commits perspective, the most visible part is the
one replacing acpi_get_first_physical_node() with
acpi_bus_get_primary_device() everywhere and dropping the former that
was inherently racy and generally unsafe to use. Fortunately, the
maintainers involved responded timely and all of that could be done
within one development cycle.
Another quite visible part is Dave Jiang's series fixing multiple
issues reported by Sashiko in the ACPI APEI support code with a PCI
AER improvement on top. It took several iterations of this to make
Sashiko happy and the code in question should be much more robust
going forward.
One other thing worth mentioning separately is that the ACPI bus type
is now going to be registered as a "companion" one and it will not be
possible to register a driver binding directly to a struct
acpi_device. All of the existing users of those drivers in the tree
were converted to platform drivers in the previous cycles, so this is
just a final step in a longer journey.
Apart from the above, there are many fixes, mostly in drivers, with a
noticeable exception of a fix in the code binding devices to their
ACPI companions, new IOVT IOMMU support in ACPICA, new _Ixx object
support for suspend-to-idle on x86, multiple new quirks, mostly
related to unused ACPI power resources and backlight handling, and
assorted cleanups.
Specifics:
- Make the core ACPI device enumeration code stop attempting to
initialize ACPI power management for devices before they are known
to be present and functional (Rafael Wysocki)
- Simplify and clean up the core ACPI device enumeration code on top
of the previous adjustment and reduce debug noise coming from it
(Rafael Wysocki)
- Fix locking in the code binding devices to their ACPI companions,
prevent it from replacing a valid ACPI companion pointer with NULL
incidentally, improve its messaging (including debug noise
reduction), and reduce its overhead by making it skip the cases in
which no ACPI companion may exist early (Rafael Wysocki)
- Reduce runtime memory footprint of struct acpi_device by
rearranging fields in it (Andy Shevchenko)
- Update the driver core to allow bus types without drivers to be
registered as "companion bus types" without driver-related sysfs
attributes and register the ACPI bus type as a companion one
(Rafael Wysocki)
- Use strscpy() instead of strcpy() in the ACPI sysfs interface
(Ruslan Vagner)
- Remove __meminitdata from hmat_adist_nb declaration preserving it
even when CONFIG_MEMORY_HOTPLUG is not set to prevent notifier
chain corruption in some cases (Alejandro Lucero)
- Prevent a NULL pointer dereference when attempting to read the
table length after a mapping bookkeeping failure during an initrd
override invocation with permanent table mappings enabled (Slavin
Liu)
- Use for_each_populated_zone() in get_node_num() in the MRRM table
pareser (Sang-Heon Jeon)
- Use vsnprintf() in acpi_os_vprintf() to prevent memory corruption
resulting from overly long diagnostic messages that may not fit
into a static buffer used by ACPICA and may be produced by a
malformed ACPI table (Vlatko Kosturjak)
- Ignore leading root scope prefix in string _UID match to allow AMD
IOMMU matching to work as expected in some cases (Mario
Limonciello)
- Adjust message printing macros for ACPI objects to use dev_fmt()
for more consistency with the analogous dev_*() macros (Rafael
Wysocki)
- Add _Ixx GPE wake indicator support to the x86 suspend-to-idle
handling code (Saranya Gopal)
- Clear driver_data before free in the ACPI PCI Link driver to
prevent a dangling pointer from being used later (Jiale Yao)
- Accumulate the queued flag across error sections of a CPER record
in ghes_do_proc() to prevent it from being cleared by a later
section or entry that does not queue memory-failure work (Breno
Leitao)
- Map a raw PCI AER Capability image field by field to prevent
information loss from occurring while processing it (Dave Jiang)
- Update a stale driver source reference in the ACPI APEI EINJ driver
documentation (Prabhakar Pujeri)
- Reject CPER records with an out-of-range error_data_length or an
error status block length wrapping a u32 in the EFI CPER driver
(Dave Jiang)
- Address multiple assorted issues in the ACPI extlog driver (Dave
Jiang)
- Address two issues related to CXL in the ACPI APEI GHES driver
(Dave Jiang)
- Read only validated fields in cper_mem_err_pack() (Dave Jiang)
- Validate memory error section length before payload access, prevent
writes past array bounds from occurring and sanitize software
metadata in the ACPI APEI GHES driver (Dave Jiang)
- Make cxl_cper_handle_prot_err() static (Dave Jiang)
- Add IOVT IOMMU support to ACPICA (Bibo Mao)
- Fix PCC OperationRegion command offsets in ACPICA (Sudeep Holla)
- Fix memory leak in acpi_ds_create_field() related to the handling
of internal_pcc_buffer allocations (Breno Leitao)
- Fix memory leak due to leftover devm_kcalloc() argument in the ACPI
fan driver (Rafael Wysocki)
- Fix backlight unregistration ordering in the ACPI video bus device
driver (Rafael Wysocki)
- Update the thermal core to allow the registration of thermal class
cooling devices under specific parents and convert the ACPI fan,
ACPI processor, and ACPI video bus device drivers to do so (Rafael
Wysocki)
- Adjust the ACPI thermal zone driver to use thermal class cooling
device parent information for binding cooling devices to trip
points in thermal zones (Rafael Wysocki)
- Use cooling device data that is a better match for a given driver
instead of a struct acpi_device pointer that had to be used for
this purpose previously in the ACPI fan and processor drivers
(Rafael Wysocki)
- Fix acpi_thermal_guess_offset() in the ACPI thermal zone driver for
thermal zone devices with a 273.0°K offset (Hans de Goede)
- Define a free for ACPI objects allocated by ACPICA helpers and use
it to simplify AML error handling in the ACPI fan driver (Rafael
Wysocki)
- Switch over the users of acpi_get_first_physical_node(), that was
inherently racy and therefore not really safe to use, to use its
replacement acpi_bus_get_primary_device(), and eliminate the former
(Rafael Wysocki)
- Add !CONFIG_ACPI stubs for acpi_find_child_device() and
acpi_device_uid() (Mario Limonciello and Robin Murphy)
- Fix bogus cycle count values on systems without _BIX in the ACPI
battery driver (Armin Wolf)
- Fix NULL pointer dereference on allocation failure and report
relative state of charge as CAPACITY in the ACPI SBS driver (Itay
Shem-tov and Guangshuo Li)
- Add lid_init_state quirk for Razer Blade Stealth 13 (Early 2020)
RZ09-0310 to the ACPI button driver (Ian Gallagher)
- Add new quirks to force the native backlight on Dell OptiPlex AIO
7410 35W and Acer Nitro AN515-58 in the ACPI video bus device
driver (Chitransh Mandhaniya and Dirga Yuza)
- Fix the shared memory signature handling in the ACPI PCC address
space handler, free the PCC mailbox channel on operation region
deactivation, and avoid unnecessary repeated computations of the
PCC operation region command timeout (Sudeep Holla)
- Fix a log message typo in the ACPI NUMA support code (Hemanth
Selam)
- Zero-initialize capability query result in the ACPI Platform
Firmware Runtime Update and Telemetry driver to avoid disclosure of
kernel stack data to user space (Karl Mehltretter)
- Replace the remaining built-in/module check for CONFIG_ACPI_WMI in
a header file with IS_ENABLED() macro (Lalit Shankar Chowdhury)
- Retry probing battery docks after hotplug in the ACPI docking
station driver to avoid missing ACPI add notifications (Vibhor
Goel)
- Detach device after resource transition failure in
pnp_device_probe() to avoid blocking later manual PNP configuration
attempts (Myeonghun Pak)"
* tag 'acpi-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (90 commits)
ACPI: PM: Add Acer Aspire A515-53G to dmi_leave_unused_power_resources_on[]
ACPI: video: force native backlight on Dell OptiPlex AIO 7410 35W
ACPI: PM: sleep: Drop unused sleep_no_lps0 define
ACPI: PM: Add unused power resource quirk for Casper Excalibur G900
ACPI: dock: Retry probing battery docks after hotplug
ACPI: PCI: pci_link: clear driver_data before free
ACPI: APEI: accumulate the queued flag across error sections
ACPICA: actbl2.h: Add bit constants of the Flags field in the IOVT IOMMU structure
ACPI: bus: Drop acpi_get_first_physical_node()
efi/dev-path-parser: Switch to use acpi_bus_get_primary_device()
ALSA: hda: tas2781: Switch to use acpi_bus_get_primary_device()
ALSA: hda: cs35l41: Switch to use acpi_bus_get_primary_device()
iommu/arm-smmu-v3: Switch to use acpi_bus_get_primary_device()
PCI/AER: Map a raw AER Capability image field by field
ACPI: NUMA: fix typo in log message
ACPI: Add stub for acpi_find_child_device()
driver core/ACPI: Introduce companion_bus_register()
ACPI: PCC: Cache OpRegion command timeout
ACPI: PCC: Free channel on OpRegion deactivation
ACPI: PCC: Preserve shared memory signature in OpRegion handler
...