kernel/linux.git/drivers/cpufreq, branch v6.12.102

cpufreq: Make cpufreq_update_pressure() fall back to cpuinfo.max_freq

2026-08-03T09:17:03+00:00

[ Upstream commit d2d5c129d07ea8eb91cd8a8633b5774116c4d171 ] If arch_scale_freq_ref() is not defined for a given arch (like x86, for example), cpufreq_update_pressure() will always set cpufreq_pressure to zero for all CPUs in the system, which is generally problematic on systems with asymmetric capacity [1]. However, in the absence of arch_scale_freq_ref(), it is reasonable to assume that cpuinfo.max_freq is the maximum sustainable frequency for the given cpufreq policy. Moreover, there are cases in which arch_scale_freq_ref() would need to be defined to return essentially the cpuinfo.max_freq value anyway (for example, intel_pstate on hybrid platforms). For the above reasons, update cpufreq_update_pressure() to fall back to using cpuinfo.max_freq as the reference frequency if zero is returned by arch_scale_freq_ref(). Fixes: 75d659317bb1 ("cpufreq: Add a cpufreq pressure feedback for the scheduler") Link: https://lore.kernel.org/lkml/CAKfTPtBuRLfYNnR4w--cFZYZy-R8gaPEgVwCcaMmbCcJ2H-muQ@mail.gmail.com/ [1] Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar Reviewed-by: Zhongqiu Han Tested-by: Ricardo Neri # cluster scheduling Acked-by: Vincent Guittot Link: https://patch.msgid.link/5086499.GXAFRqVoOG@rafael.j.wysocki Signed-off-by: Sasha Levin

cpufreq: intel_pstate: Set non-turbo capacity to HWP_GUARANTEED_PERF()

2026-07-24T14:11:30+00:00

commit 27d80e0f8b8dff97503fc0061754b1d3800cb961 upstream. Setting cpu->capacity_perf to cpu->pstate.max_pstate_physical in the "no turbo" case is inconsistent with what happens elsewhere in the driver and causes arch_scale_cpu_capacity() to be incorrect. It also skews arch_scale_freq_capacity() which ends up differing from 1024 for the guaranteed P-state. Address that by setting capacity_perf to HWP_GUARANTEED_PERF() in the "no turbo" case. Fixes: 929ebc93ccaa ("cpufreq: intel_pstate: Set asymmetric CPU capacity on hybrid systems") Signed-off-by: Rafael J. Wysocki Tested-by: Ricardo Neri Cc: All applicable Link: https://patch.msgid.link/12928972.O9o76ZdvQC@rafael.j.wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: conservative: Simplify frequency limit handling

2026-07-24T14:10:48+00:00

[ Upstream commit 3494dff89779b73a6c70481c982e0e96d336454a ] cs_dbs_update() performs explicit checks against policy->min/max before updating the target frequency. These checks are redundant as __cpufreq_driver_target() already clamps the requested frequency to the valid policy limits. Remove the unnecessary boundary checks and simplify the update logic. This also fixes an issue introduced by commit 00bfe05889e9 ("cpufreq: conservative: Decrease frequency faster for deferred updates"), where stale target comparisons could cause frequency updates to be skipped entirely after deferred adjustments. Closes: https://lore.kernel.org/all/20260421123545.1745998-1-zhenglifeng1@huawei.com/ Fixes: 00bfe05889e9 ("cpufreq: conservative: Decrease frequency faster for deferred updates") Signed-off-by: Lifeng Zheng Co-developed-by: Viresh Kumar Signed-off-by: Viresh Kumar Reviewed-by: Zhongqiu Han Link: https://patch.msgid.link/292e6d937890f135e30ec0d2107eaad47cb9a976.1779423281.git.viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

cpufreq: pcc: fix use-after-free and double free in _OSC evaluation

2026-07-18T14:52:06+00:00

commit 266d3dd8b757b48a576e90f018b51f7b7563cc32 upstream. pcc_cpufreq_do_osc() calls acpi_evaluate_object() twice for the two-phase _OSC negotiation. Between the two calls it freed output.pointer but left output.length unchanged. Since acpi_evaluate_object() treats a non-zero length with a non-NULL pointer as an existing buffer to write into, the second call wrote into freed memory (use-after-free). The subsequent kfree(output.pointer) at out_free then freed the same pointer a second time (double free). Reset output.pointer to NULL and output.length to ACPI_ALLOCATE_BUFFER after freeing the first result, so ACPICA allocates a fresh buffer for each phase independently. Fixes: 0f1d683fb35d ("[CPUFREQ] Processor Clocking Control interface driver") Signed-off-by: Yuho Choi Reviewed-by: Zhongqiu Han Cc: All applicable Link: https://patch.msgid.link/20260416144621.93964-1-dbgh9129@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix hotplug-suspend race during reboot

2026-07-18T14:52:06+00:00

commit a9029dd55696c651ee46912afa2a166fa456bb3e upstream. During system reboot, cpufreq_suspend() is called via the kernel_restart() -> device_shutdown() path. Unlike the normal system suspend path, the reboot path does not call freeze_processes(), so userspace processes and kernel threads remain active. This allows CPU hotplug operations to run concurrently with cpufreq_suspend(). The original code has no synchronization with CPU hotplug, leading to a race condition where governor_data can be freed by the hotplug path while cpufreq_suspend() is still accessing it, resulting in a null pointer dereference: Unable to handle kernel NULL pointer dereference Call Trace: do_kernel_fault+0x28/0x3c cpufreq_suspend+0xdc/0x160 device_shutdown+0x18/0x200 kernel_restart+0x40/0x80 arm64_sys_reboot+0x1b0/0x200 Fix this by adding cpus_read_lock()/cpus_read_unlock() to cpufreq_suspend() to block CPU hotplug operations while suspend is in progress. Fixes: 65650b35133f ("cpufreq: Avoid cpufreq_suspend() deadlock on system shutdown") Signed-off-by: Tianxiang Chen Reviewed-by: Zhongqiu Han Cc: All applicable [ rjw: Changelog edits ] Link: https://patch.msgid.link/20260408141914.35281-1-nanmu@xiaomi.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: intel_pstate: Sync policy->cur during CPU offline

2026-07-18T14:52:06+00:00

commit bcbdaa1086c25a8a5d48e04e1b82fdfb0682b681 upstream. When a CPU goes offline with HWP disabled, intel_pstate_set_min_pstate() sets the MSR_IA32_PERF_CTL to minimum frequency to prevent SMT siblings from being restricted. However, the policy->cur value was not updated, leaving it at the previous value. When the CPU comes back online, governor->limits() checks if target_freq equals policy->cur and skips the frequency adjustment if they match. Since policy->cur still holds the previous value, the governor does not call cpufreq_driver->target to update MSR_IA32_PERF_CTL. Fix this by synchronizing policy->cur with the hardware state when setting minimum pstate during CPU offline. Fixes: bb18008f8086 ("intel_pstate: Set core to min P state during core offline") Cc: stable@vger.kernel.org # 3.15+ Suggested-by: Srinivas Pandruvada Signed-off-by: Fushuai Wang [ rjw: Subject refinement ] Link: https://patch.msgid.link/20260520032119.30615-1-fushuai.wang@linux.dev Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: qcom-cpufreq-hw: Fix possible double free

2026-07-18T14:52:06+00:00

commit bcb8889c4981fdde42d4fd2c29a77d510fe21da2 upstream. qcom_cpufreq.data is allocated with devm_kzalloc() in probe() as an array of per-domain data. qcom_cpufreq_hw_cpu_init() stores a pointer to one element of this array in policy->driver_data. qcom_cpufreq_hw_cpu_exit() currently calls kfree() on policy->driver_data. This is not valid because the memory is devm-managed. For the first domain, this can free the devm-managed allocation while the devres entry is still active, leading to a possible double free when the platform device is later detached. For other domains, the pointer may refer to an element inside the array rather than the allocation base. Remove the kfree(data) call and let devres release qcom_cpufreq.data. This issue was found by a static analysis tool I am developing. Fixes: 054a3ef683a1 ("cpufreq: qcom-hw: Allocate qcom_cpufreq_data during probe") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li Reviewed-by: Zhongqiu Han Signed-off-by: Viresh Kumar Signed-off-by: Greg Kroah-Hartman

cpufreq: governor: fix double free in cpufreq_dbs_governor_init() error path

2026-04-11T12:24:49+00:00

commit 6dcf9d0064ce2f3e3dfe5755f98b93abe6a98e1e upstream. When kobject_init_and_add() fails, cpufreq_dbs_governor_init() calls kobject_put(&dbs_data->attr_set.kobj). The kobject release callback cpufreq_dbs_data_release() calls gov->exit(dbs_data) and kfree(dbs_data), but the current error path then calls gov->exit(dbs_data) and kfree(dbs_data) again, causing a double free. Keep the direct kfree(dbs_data) for the gov->init() failure path, but after kobject_init_and_add() has been called, let kobject_put() handle the cleanup through cpufreq_dbs_data_release(). Fixes: 4ebe36c94aed ("cpufreq: Fix kobject memleak") Signed-off-by: Guangshuo Li Reviewed-by: Zhongqiu Han Acked-by: Viresh Kumar Cc: All applicable Link: https://patch.msgid.link/20260401024535.1395801-1-lgs201920130244@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: conservative: Reset requested_freq on limits change

2026-04-02T11:09:42+00:00

commit 6a28fb8cb28b9eb39a392e531d938a889eacafc5 upstream. A recently reported issue highlighted that the cached requested_freq is not guaranteed to stay in sync with policy->cur. If the platform changes the actual CPU frequency after the governor sets one (e.g. due to platform-specific frequency scaling) and a re-sync occurs later, policy->cur may diverge from requested_freq. This can lead to incorrect behavior in the conservative governor. For example, the governor may assume the CPU is already running at the maximum frequency and skip further increases even though there is still headroom. Avoid this by resetting the cached requested_freq to policy->cur on detecting a change in policy limits. Reported-by: Lifeng Zheng Tested-by: Lifeng Zheng Link: https://lore.kernel.org/all/20260210115458.3493646-1-zhenglifeng1@huawei.com/ Signed-off-by: Viresh Kumar Reviewed-by: Zhongqiu Han Cc: All applicable Link: https://patch.msgid.link/d846a141a98ac0482f20560fcd7525c0f0ec2f30.1773999467.git.viresh.kumar@linaro.org Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: dt-platdev: Block the driver from probing on more QC platforms

2026-03-04T12:20:55+00:00

[ Upstream commit 7b781899072c5701ef9538c365757ee9ab9c00bd ] Add a number of QC platforms to the blocklist, they all use either the qcom-cpufreq-hw driver. Signed-off-by: Konrad Dybcio Signed-off-by: Viresh Kumar Signed-off-by: Sasha Levin