The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 9e4e249018d208678888bdf22f6b652728106528 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025041718-elastic-salutary-56db@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9e4e249018d208678888bdf22f6b652728106528 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" rafael.j.wysocki@intel.com Date: Fri, 28 Mar 2025 21:39:08 +0100 Subject: [PATCH] cpufreq: Reference count policy in cpufreq_update_limits() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
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
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 0cf5a320bb5e..3841c9da6cac 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2809,6 +2809,12 @@ EXPORT_SYMBOL(cpufreq_update_policy); */ 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