kernel/linux.git/drivers/acpi/power.c, branch linux-7.1.y

ACPI: scan: Use acpi_dev_put() in object add error paths

2026-04-15T14:43:58+00:00

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 Signed-off-by: Guangshuo Li Link: https://patch.msgid.link/20260413135343.2884481-1-lgs201920130244@gmail.com Signed-off-by: Rafael J. Wysocki

ACPI: driver: Do not set acpi_device_class() unnecessarily

2026-03-13T15:48:26+00:00

Several core ACPI device drivers set acpi_device_class() for the given struct acpi_device to whatever they like, but that value is never used unless the driver itself uses it and, sadly, they neglect to clear it on remove. Since the only one of them still using acpi_device_class() after previous changes is the button driver, update the others to stop setting it in vain. Also drop the related device class sybmols that become redundant. Since the ACPI button driver continues to use acpi_device_class(), make it clear the struct field represented by acpi_device_class() in its remove callback. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/3706295.iIbC2pHGDl@rafael.j.wysocki

ACPI: driver: Do not set acpi_device_name() unnecessarily

2026-03-13T15:48:23+00:00

ACPI drivers usually set acpi_device_name() for the given struct acpi_device to whatever they like, but that value is never used unless the driver itself uses it and, quite unfortunately, drivers neglect to clear it on remove. Some drivers use it for printing messages or initializing the names of subordinate devices, but it is better to use string literals for that, especially if the given one is used just once. To eliminate unnecessary overhead related to acpi_device_name() handling, rework multiple core ACPI device drivers to stop setting acpi_device_name() for struct acpi_device objects manipulated by them and use a string literal instead of it where applicable. No intentional functional impact. Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/10840483.nUPlyArG6x@rafael.j.wysocki

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

ACPI: PM: Add unused power resource quirk for THUNDEROBOT ZERO

2026-02-16T17:22:15+00:00

On the THUNDEROBOT ZERO laptop, the second NVMe slot and the discrete NVIDIA GPU are both controlled by power-resource PXP. Due to the SSDT table bug (lack of reference), PXP will be shut dow as an "unused" power resource during initialization, making the NVMe slot #2 + NVIDIA both inaccessible. This issue was introduced by commit a1224f34d72a ("ACPI: PM: Check states of power resources during initialization"). Here are test results on the three consecutive commits: (bad again!) a1224f34d72a ACPI: PM: Check states of power resources during initialization (good) bc2836859643 ACPI: PM: Do not turn off power resources in unknown state (bad) 519d81956ee2 Linux 5.15-rc6 On commit bc2836859643 ("ACPI: PM: Do not turn off power resources in unknown state") this was not an issue because the power resource state left UNKNOWN thus being ignored. See also commit 9b04d99788cf ("ACPI: PM: Do not turn of unused power resources on the Toshiba Click Mini") which is another almost identical case to this one. Fixes: a1224f34d72a ("ACPI: PM: Check states of power resources during initialization") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221087 Signed-off-by: Zhai Can Link: https://patch.msgid.link/20260214161452.2849346-1-bczhc0@126.com Signed-off-by: Rafael J. Wysocki

ACPI: PM: Add HP EliteBook 855 G7 WWAN modem power resource quirk

2025-08-25T14:25:54+00:00

This laptop (and possibly similar models too) has power resource called "GP12.PXP_" for its Intel XMM7360 WWAN modem. For this power resource to turn ON power for the modem it needs certain internal flag called "ONEN" to be set: Method (_ON, 0, NotSerialized) // _ON_: Power On { If (^^^LPCB.EC0.ECRG) { If ((ONEN == Zero)) { Return (Zero) } (..) } } This flag only gets set from this power resource _OFF method, while the actual modem power gets turned off during suspend by "GP12.PTS" method called from the global _PTS (Prepare To Sleep) method. In fact, this power resource _OFF method implementation just sets the aforementioned flag: Method (_OFF, 0, NotSerialized) // _OFF: Power Off { OFEN = Zero ONEN = One } Upon hibernation finish, the kernel tries to set this power resource back ON since its _STA method returns 0 and the resource is still considered in use as it is declared as required for D0 for both the modem ACPI device (GP12.PWAN) and its parent PCIe port ACPI device object (GP12). But the _ON method won't do anything since that "ONEN" flag is not set. Overall, this means the modem is dead after hibernation finish until the laptop is rebooted since the modem power has been cut by _PTS and its PCI configuration was lost and not able to be restored. The easiest way to workaround this issue is to call this power resource _OFF method before calling the _ON method to make sure the "ONEN" flag gets properly set. This makes the modem alive once again after hibernation finish - with properly restored PCI configuration space. Since this platform does *not* support S3 the fact that acpi_resume_power_resources() is also called during resume from S3 is not a problem there. Do the DMI based quirk matching and quirk flag initialization just once - in acpi_power_resources_init() function. This way the whole resume path overhead of this change on other systems amounts to simple hp_eb_gp12pxp_quirk flag comparison. Signed-off-by: Maciej S. Szmigiero Link: https://patch.msgid.link/c6ff6931c5d27592052f30339de1b9cc298c43f0.1754243159.git.mail@maciej.szmigiero.name [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: PM: Add power resource init function

2025-08-25T14:25:54+00:00

This way DMI based quirk matching and quirk flag initialization can be done just once - in the newly introduced acpi_power_resources_init() function, which is similar to existing acpi_*_init() functions. Convert the single already existing DMI match-based quirk in this ACPI power resource handler ("leave unused power resources on" quirk) to such one-time initialization in acpi_power_resources_init() function instead of re-running that DMI match each time acpi_turn_off_unused_power_resources() gets called. Signed-off-by: Maciej S. Szmigiero Link: https://patch.msgid.link/b173a6987f0b35597fd82400cb28f289786e03d0.1754243159.git.mail@maciej.szmigiero.name Signed-off-by: Rafael J. Wysocki

ACPI: power: Use str_on_off() helper function

2025-02-18T17:48:32+00:00

Use the str_on_off() helper function instead of hard-coded strings. Signed-off-by: Thorsten Blum Link: https://patch.msgid.link/20250209220835.78434-2-thorsten.blum@linux.dev [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

ACPI: power: Use strscpy() instead of strcpy()

2024-11-05T20:35:36+00:00

Replace strcpy() with strscpy() in the ACPI power resource driver. strcpy() has been deprecated because it is generally unsafe, so it is better to eliminate it from the kernel source. Link: https://github.com/KSPP/linux/issues/88 Signed-off-by: Muhammad Qasim Abdul Majeed Link: https://patch.msgid.link/20240915183822.34588-6-qasim.majeed20@gmail.com [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki