linux-next.git/drivers/devfreq/devfreq.c, branch master

PM / devfreq: Fix governor_store() failing when device has no current governor

2026-05-10T12:53:44+00:00

Since devfreq_remove_governor() may clear the device's current governor in certain situations, while governors actually exist independently of the device, directly returning EINVAL in this case is inaccurate. To fix this issue, remove this check and add relevant logic for when df->governor is NULL. Fixes: 483d557ee9a3 ("PM / devfreq: Clean up the devfreq instance name in sysfs attr") Co-developed-by: Choi Chanwoo Signed-off-by: Yaxiong Tian Signed-off-by: Chanwoo Choi Link: https://lore.kernel.org/all/20260430032035.75496-1-tianyaxiong@kylinos.cn/

PM / devfreq: Optimize error return value of governor_show()

2026-04-29T22:06:44+00:00

When df->governor is NULL, governor_show() returns -EINVAL, which confuses users. To fix this issue, return -ENOENT to indicate that no governor is currently set for the device. Signed-off-by: Yaxiong Tian Signed-off-by: Chanwoo Choi Link: https://patchwork.kernel.org/project/linux-pm/patch/20260401033128.67925-1-tianyaxiong@kylinos.cn/

PM / devfreq: Fix available_governors_show() when no governor is set

2026-04-29T21:47:06+00:00

Since devfreq_remove_governor() may clear the device's current governor in certain situations, while governors actually exist independently of the device, directly returning EINVAL in this case is inaccurate. To fix this issue, remove this check and use df->governor for validity verification in the following code. Fixes: 483d557ee9a3 ("PM / devfreq: Clean up the devfreq instance name in sysfs attr") Signed-off-by: Yaxiong Tian Reviewed-by: Jie Zhan Signed-off-by: Chanwoo Choi Link: https://patchwork.kernel.org/project/linux-pm/patch/20260401033055.67608-1-tianyaxiong@kylinos.cn/

PM / devfreq: Fix possible null pointer issue in devfreq_add_governor()

2026-04-29T21:47:05+00:00

When a user removes a governor using devfreq_remove_governor(), if the current device is using this governor, devfreq->governor will be set to NULL. When the user registers any governor using devfreq_add_governor(), since devfreq->governor is NULL, a null pointer error occurs in strncmp(). For example: A user loads the userspace gov through a module, then a device selects userspace. When unloading the userspace module and then loading it again, the null pointer error occurs: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits *******************skip ********************* Call trace: __pi_strncmp+0x20/0x1b8 devfreq_userspace_init+0x1c/0xff8 [governor_userspace] do_one_initcall+0x4c/0x278 do_init_module+0x5c/0x218 load_module+0x1f1c/0x1fc8 init_module_from_file+0x8c/0xd0 __arm64_sys_finit_module+0x220/0x3d8 invoke_syscall+0x48/0x110 el0_svc_common.constprop.0+0xbc/0xe8 do_el0_svc+0x20/0x30 el0_svc+0x24/0xb8 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x14c/0x150 To fix this issue, remove the list_for_each_entry() logic, as find_devfreq_governor() has already checked for the existence of governor with the same name. This makes it impossible to find a duplicate governor in the list, so the subsequent logic is unreachable and can be removed. Fixes: 1b5c1be2c88e ("PM / devfreq: map devfreq drivers to governor using name") Signed-off-by: Yaxiong Tian Co-developed-by: Jie Zhan Signed-off-by: Jie Zhan Signed-off-by: Chanwoo Choi Link: https://patchwork.kernel.org/project/linux-pm/patch/20260401033046.67482-1-tianyaxiong@kylinos.cn/

PM / devfreq: use _visible attribute to replace create/remove_sysfs_files()

2026-04-03T18:15:38+00:00

Previously, non-generic attributes (polling_interval, timer) used separate create/delete logic, leading to race conditions during concurrent access in creation/deletion. Multi-threaded operations also caused inconsistencies between governor capabilities and attribute states. 1.Use is_visible + sysfs_update_group() to unify management of these attributes, eliminating creation/deletion races. 2.Add locks and validation to these attributes, ensuring consistency between current governor capabilities and attribute operations in multi-threaded environments. Reviewed-by: Jonathan Cameron Reviewed-by: Jie Zhan Signed-off-by: Pengjie Zhang Signed-off-by: Chanwoo Choi Link: https://www.spinics.net/lists/kernel/msg5967745.html

PM / devfreq: Remove unneeded casting for HZ_PER_KHZ

2026-04-03T18:15:38+00:00

HZ_PER_KHZ is defined as UL (unsigned long), no need to repeat that. Signed-off-by: Andy Shevchenko Reviewed-by: Lifeng Zheng Acked-by: MyungJoo Ham Signed-off-by: Chanwoo Choi Link: https://lore.kernel.org/lkml/20260114093115.276818-1-andriy.shevchenko@linux.intel.com/

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

PM / devfreq: Move governor.h to a public header location

2025-11-23T15:02:01+00:00

Some device drivers (and out-of-tree modules) might want to define device-specific device governors. Rather than restricting all of them to be a part of drivers/devfreq/ (which is not possible for out-of-tree drivers anyway) move governor.h to include/linux/devfreq-governor.h and update all drivers to use it. The devfreq_cpu_data is only used internally, by the passive governor, so it is moved to the driver source rather than being a part of the public interface. Reported-by: Robie Basak Acked-by: Jon Hunter Signed-off-by: Dmitry Baryshkov Reviewed-by: Bjorn Andersson Acked-by: MyungJoo Ham Signed-off-by: Chanwoo Choi Link: https://patchwork.kernel.org/project/linux-pm/patch/20251030-governor-public-v2-1-432a11a9975a@oss.qualcomm.com/

PM / devfreq: Allow devfreq driver to add custom sysfs ABIs

2025-07-14T11:22:59+00:00

Extend the devfreq_dev_profile to allow drivers optionally create device-specific sysfs ABIs together with other common devfreq ABIs under the devfreq device path. Reviewed-by: Jonathan Cameron Reviewed-by: Huisong Li Signed-off-by: Jie Zhan Signed-off-by: Chanwoo Choi Link: https://patchwork.kernel.org/project/linux-pm/patch/20250623143401.4095045-2-zhanjie9@hisilicon.com/