kernel.git/drivers/cpufreq/cpufreq.c, branch linux-5.4.y

cpufreq: Exit governor when failed to start old governor

2025-08-28T14:21:25Z

[ Upstream commit 0ae204405095abfbc2d694ee0fbb49bcbbe55c57 ] Detect the result of starting old governor in cpufreq_set_policy(). If it fails, exit the governor and clear policy->governor. Signed-off-by: Lifeng Zheng Link: https://patch.msgid.link/20250709104145.2348017-5-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Init policy->rwsem before it may be possibly used

2025-08-28T14:21:19Z

[ Upstream commit d1378d1d7edb3a4c4935a44fe834ae135be03564 ] In cpufreq_policy_put_kobj(), policy->rwsem is used. But in cpufreq_policy_alloc(), if freq_qos_add_notifier() returns an error, error path via err_kobj_remove or err_min_qos_notifier will be reached and cpufreq_policy_put_kobj() will be called before policy->rwsem is initialized. Thus, the calling of init_rwsem() should be moved to where before these two error paths can be reached. Fixes: 67d874c3b2c6 ("cpufreq: Register notifiers with the PM QoS framework") Signed-off-by: Lifeng Zheng Link: https://patch.msgid.link/20250709104145.2348017-3-zhenglifeng1@huawei.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Force sync policy boost with global boost on sysfs update

2025-06-27T10:02:54Z

[ Upstream commit 121baab7b88ed865532dadb7ef1aee6e2bea86f5 ] If the global boost flag is enabled and policy boost flag is disabled, a call to `cpufreq_boost_trigger_state(true)` must enable the policy's boost state. The current code misses that because of an optimization. Fix it. Suggested-by: Lifeng Zheng Reviewed-by: Lifeng Zheng Signed-off-by: Viresh Kumar Link: https://patch.msgid.link/852ff11c589e6300730d207baac195b2d9d8b95f.1745511526.git.viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Reference count policy in cpufreq_update_limits()

2025-05-02T05:39:21Z

commit 9e4e249018d208678888bdf22f6b652728106528 upstream. Since acpi_processor_notify() can be called before registering a cpufreq driver or even in cases when a cpufreq driver is not registered at all, cpufreq_update_limits() needs to check if a cpufreq driver is present and prevent it from being unregistered. For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq policy pointer for the given CPU and reference count the corresponding policy object, if present. Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates") Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl Reported-by: Marek Marczykowski-Górecki Cc: All applicable Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Link: https://patch.msgid.link/1928789.tdWV9SEqCh@rjwysocki.net [do not use __free(cpufreq_cpu_put) in a backport] Signed-off-by: Marek Marczykowski-GÃ³recki Signed-off-by: Greg Kroah-Hartman

cpufreq: exit() callback is optional

2024-06-16T11:28:34Z

[ Upstream commit b8f85833c05730d631576008daaa34096bc7f3ce ] The exit() callback is optional and shouldn't be called without checking a valid pointer first. Also, we must clear freq_table pointer even if the exit() callback isn't present. Signed-off-by: Viresh Kumar Fixes: 91a12e91dc39 ("cpufreq: Allow light-weight tear down and bring up of CPUs") Fixes: f339f3541701 ("cpufreq: Rearrange locking in cpufreq_remove_dev()") Reported-by: Lizhe Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Rearrange locking in cpufreq_remove_dev()

2024-06-16T11:28:34Z

[ Upstream commit f339f3541701d824a0256ad4bf14c26ceb6d79c3 ] Currently, cpufreq_remove_dev() invokes the ->exit() driver callback without holding the policy rwsem which is inconsistent with what happens if ->exit() is invoked directly from cpufreq_offline(). It also manipulates the real_cpus mask and removes the CPU device symlink without holding the policy rwsem, but cpufreq_offline() holds the rwsem around the modifications thereof. For consistency, modify cpufreq_remove_dev() to hold the policy rwsem until the ->exit() callback has been called (or it has been determined that it is not necessary to call it). Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Stable-dep-of: b8f85833c057 ("cpufreq: exit() callback is optional") Signed-off-by: Sasha Levin

cpufreq: Split cpufreq_offline()

2024-06-16T11:28:34Z

[ Upstream commit fddd8f86dff4a24742a7f0322ccbb34c6c1c9850 ] Split the "core" part running under the policy rwsem out of cpufreq_offline() to allow the locking in cpufreq_remove_dev() to be rearranged more easily. As a side-effect this eliminates the unlock label that's not needed any more. No expected functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Stable-dep-of: b8f85833c057 ("cpufreq: exit() callback is optional") Signed-off-by: Sasha Levin

cpufreq: Reorganize checks in cpufreq_offline()

2024-06-16T11:28:34Z

[ Upstream commit e1e962c5b9edbc628a335bcdbd010331a12d3e5b ] Notice that cpufreq_offline() only needs to check policy_is_inactive() once and rearrange the code in there to make that happen. No expected functional impact. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Stable-dep-of: b8f85833c057 ("cpufreq: exit() callback is optional") Signed-off-by: Sasha Levin

cpufreq: Fix the race condition while updating the transition_task of policy

2023-09-23T08:59:53Z

[ Upstream commit 61bfbf7951ba561dcbdd5357702d3cbc2d447812 ] The field 'transition_task' of policy structure is used to track the task which is performing the frequency transition. Using this field to print a warning once detect a case where the same task is calling _begin() again before completing the preivous frequency transition via the _end(). However, there is a potential race condition in _end() and _begin() APIs while updating the field 'transition_task' of policy, the scenario is depicted below: Task A Task B /* 1st freq transition */ Invoke _begin() { ... ... } /* 2nd freq transition */ Invoke _begin() { ... //waiting for A to ... //clear ... //transition_ongoing ... //in _end() for ... //the 1st transition | Change the frequency | | Invoke _end() { | ... | ... | transition_ongoing = false; V transition_ongoing = true; transition_task = current; transition_task = NULL; ... //A overwrites the task ... //performing the transition ... //result in error warning. } To fix this race condition, the transition_lock of policy structure is now acquired before updating policy structure in _end() API. Which ensure that only one task can update the 'transition_task' field at a time. Link: https://lore.kernel.org/all/b3c61d8a-d52d-3136-fbf0-d1de9f1ba411@huawei.com/ Fixes: ca654dc3a93d ("cpufreq: Catch double invocations of cpufreq_freq_transition_begin/end") Signed-off-by: Liao Chang Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: Init completion before kobject_init_and_add()

2023-01-18T10:41:46Z

commit 5c51054896bcce1d33d39fead2af73fec24f40b6 upstream. In cpufreq_policy_alloc(), it will call uninitialed completion in cpufreq_sysfs_release() when kobject_init_and_add() fails. And that will cause a crash such as the following page fault in complete: BUG: unable to handle page fault for address: fffffffffffffff8 [..] RIP: 0010:complete+0x98/0x1f0 [..] Call Trace: kobject_put+0x1be/0x4c0 cpufreq_online.cold+0xee/0x1fd cpufreq_add_dev+0x183/0x1e0 subsys_interface_register+0x3f5/0x4e0 cpufreq_register_driver+0x3b7/0x670 acpi_cpufreq_init+0x56c/0x1000 [acpi_cpufreq] do_one_initcall+0x13d/0x780 do_init_module+0x1c3/0x630 load_module+0x6e67/0x73b0 __do_sys_finit_module+0x181/0x240 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: 4ebe36c94aed ("cpufreq: Fix kobject memleak") Signed-off-by: Yongqiang Liu Acked-by: Viresh Kumar Cc: 5.2+ # 5.2+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman