On 4/18/2025 4:15 AM, Marek Marczykowski-Górecki wrote:
From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com
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 marmarek@invisiblethingslab.com Cc: All applicable stable@vger.kernel.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Acked-by: Viresh Kumar viresh.kumar@linaro.org Link: https://patch.msgid.link/1928789.tdWV9SEqCh@rjwysocki.net (cherry picked from commit 9e4e249018d208678888bdf22f6b652728106528) [do not use __free(cpufreq_cpu_put) in a backport] Signed-off-by: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com
This patch is applicable to other stable branches too.
Thanks a lot for taking care of backporting it!
drivers/cpufreq/cpufreq.c | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 30ffbddc7ece..934e0e19824c 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2762,10 +2762,18 @@ EXPORT_SYMBOL(cpufreq_update_policy); */ void cpufreq_update_limits(unsigned int cpu) {
- struct cpufreq_policy *policy;
- policy = cpufreq_cpu_get(cpu);
- if (!policy)
return;- if (cpufreq_driver->update_limits) cpufreq_driver->update_limits(cpu); else cpufreq_update_policy(cpu);
- cpufreq_cpu_put(policy); } EXPORT_SYMBOL_GPL(cpufreq_update_limits);