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| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2025-03-28 23:39:08 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-25 11:44:00 +0300 |
| commit | 0bf87fafc190904bd57a584c2834bc5ea2976103 (patch) | |
| tree | f46991a0a5fd624c6d22133f051e269d5c9b7893 /drivers/cpufreq | |
| parent | 17c7f46efb262257fb1b6883202ffa02a87569a1 (diff) | |
| download | linux-0bf87fafc190904bd57a584c2834bc5ea2976103.tar.xz | |
cpufreq: Reference count policy in cpufreq_update_limits()
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 <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
[do not use __free(cpufreq_cpu_put) in a backport]
Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 04d89cf0d71d..779ec6e510f7 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2673,10 +2673,18 @@ 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); |