On Fri, Mar 28, 2025 at 09:39:08PM +0100, Rafael J. Wysocki 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 Reporetd-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
It looks like this patch is missing in stable branches.
drivers/cpufreq/cpufreq.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2781,6 +2781,12 @@ */ void cpufreq_update_limits(unsigned int cpu) {
- struct cpufreq_policy *policy __free(put_cpufreq_policy);
- policy = cpufreq_cpu_get(cpu);
- if (!policy)
return;- if (cpufreq_driver->update_limits) cpufreq_driver->update_limits(cpu); else