From 7a73801fdaf8aee90d23ba77976082a48d156a21 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 22 Dec 2025 21:29:41 +0100 Subject: [PATCH 1/4] pmdomain: imx: gpcv2: Discard pm_runtime_put() return value Passing pm_runtime_put() return value to the callers is not particularly useful. Returning an error code from pm_runtime_put() merely means that it has not queued up a work item to check whether or not the device can be suspended and there are many perfectly valid situations in which that can happen, like after writing "on" to the devices' runtime PM "control" attribute in sysfs for one example. Accordingly, update imx_pgc_domain_suspend() to simply discard the return value of pm_runtime_put() and always return success to the caller. This will facilitate a planned change of the pm_runtime_put() return type to void in the future. Signed-off-by: Rafael J. Wysocki Acked-by: Peng Fan Acked-by: Ulf Hansson Link: https://patch.msgid.link/15658107.tv2OnDr8pf@rafael.j.wysocki --- drivers/pmdomain/imx/gpcv2.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/pmdomain/imx/gpcv2.c b/drivers/pmdomain/imx/gpcv2.c index cff738e4d546..a829f8da5be7 100644 --- a/drivers/pmdomain/imx/gpcv2.c +++ b/drivers/pmdomain/imx/gpcv2.c @@ -1416,7 +1416,9 @@ static int imx_pgc_domain_suspend(struct device *dev) static int imx_pgc_domain_resume(struct device *dev) { - return pm_runtime_put(dev); + pm_runtime_put(dev); + + return 0; } #endif From 3afd8df024339c7da1a5a0302f3987866dd16e40 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 22 Dec 2025 21:36:25 +0100 Subject: [PATCH 2/4] PM: runtime: Change pm_runtime_put() return type to void The primary role of pm_runtime_put() is to decrement the runtime PM usage counter of the given device. It always does that regardless of the value returned by it later. In addition, if the runtime PM usage counter after decrementation turns out to be zero, a work item is queued up to check whether or not the device can be suspended. This is not guaranteed to succeed though and even if it is successful, the device may still not be suspended going forward. There are multiple valid reasons why pm_runtime_put() may not decide to queue up the work item mentioned above, including, but not limited to, the case when user space has written "on" to the device's runtime PM "control" file in sysfs. In all of those cases, pm_runtime_put() returns a negative error code (even though the device's runtime PM usage counter has been successfully decremented by it) which is very confusing. In fact, its return value should only be used for debug purposes and care should be taken when doing it even in that case. Accordingly, to avoid the confusion mentioned above, change the return type of pm_runtime_put() to void. Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Reviewed-by: Brian Norris Link: https://patch.msgid.link/14387202.RDIVbhacDa@rafael.j.wysocki --- include/linux/pm_runtime.h | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 41037c513f06..64921b10ac74 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -545,22 +545,10 @@ static inline int pm_runtime_resume_and_get(struct device *dev) * * Decrement the runtime PM usage counter of @dev and if it turns out to be * equal to 0, queue up a work item for @dev like in pm_request_idle(). - * - * Return: - * * 1: Success. Usage counter dropped to zero, but device was already suspended. - * * 0: Success. - * * -EINVAL: Runtime PM error. - * * -EACCES: Runtime PM disabled. - * * -EAGAIN: Runtime PM usage counter became non-zero or Runtime PM status - * change ongoing. - * * -EBUSY: Runtime PM child_count non-zero. - * * -EPERM: Device PM QoS resume latency 0. - * * -EINPROGRESS: Suspend already in progress. - * * -ENOSYS: CONFIG_PM not enabled. */ -static inline int pm_runtime_put(struct device *dev) +static inline void pm_runtime_put(struct device *dev) { - return __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC); + __pm_runtime_idle(dev, RPM_GET_PUT | RPM_ASYNC); } /** From ab39cc4cb8ceecdc2b61747433e7237f1ac2b789 Mon Sep 17 00:00:00 2001 From: David Arcari Date: Tue, 24 Feb 2026 07:21:06 -0500 Subject: [PATCH 3/4] cpufreq: intel_pstate: Fix NULL pointer dereference in update_cpu_qos_request() The update_cpu_qos_request() function attempts to initialize the 'freq' variable by dereferencing 'cpudata' before verifying if the 'policy' is valid. This issue occurs on systems booted with the "nosmt" parameter, where all_cpu_data[cpu] is NULL for the SMT sibling threads. As a result, any call to update_qos_requests() will result in a NULL pointer dereference as the code will attempt to access pstate.turbo_freq using the NULL cpudata pointer. Also, pstate.turbo_freq may be updated by intel_pstate_get_hwp_cap() after initializing the 'freq' variable, so it is better to defer the 'freq' until intel_pstate_get_hwp_cap() has been called. Fix this by deferring the 'freq' assignment until after the policy and driver_data have been validated. Fixes: ae1bdd23b99f ("cpufreq: intel_pstate: Adjust frequency percentage computations") Reported-by: Jirka Hladky Closes: https://lore.kernel.org/all/CAE4VaGDfiPvz3AzrwrwM4kWB3SCkMci25nPO8W1JmTBd=xHzZg@mail.gmail.com/ Signed-off-by: David Arcari Cc: 6.18+ # 6.18+ [ rjw: Added one paragraph to the changelog ] Link: https://patch.msgid.link/20260224122106.228116-1-darcari@redhat.com Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index a48af3540c74..bdc37080d319 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1647,8 +1647,8 @@ static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b, static void update_cpu_qos_request(int cpu, enum freq_qos_req_type type) { struct cpudata *cpudata = all_cpu_data[cpu]; - unsigned int freq = cpudata->pstate.turbo_freq; struct freq_qos_request *req; + unsigned int freq; struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu); if (!policy) @@ -1661,6 +1661,8 @@ static void update_cpu_qos_request(int cpu, enum freq_qos_req_type type) if (hwp_active) intel_pstate_get_hwp_cap(cpudata); + freq = cpudata->pstate.turbo_freq; + if (type == FREQ_QOS_MIN) { freq = DIV_ROUND_UP(freq * global.min_perf_pct, 100); } else { From 6b050482ec40569429d963ac52afa878691b04c9 Mon Sep 17 00:00:00 2001 From: Srinivas Pandruvada Date: Tue, 24 Feb 2026 16:17:52 -0800 Subject: [PATCH 4/4] cpufreq: intel_pstate: Fix crash during turbo disable When the system is booted with kernel command line argument "nosmt" or "maxcpus" to limit the number of CPUs, disabling turbo via: echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo results in a crash: PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI ... RIP: 0010:store_no_turbo+0x100/0x1f0 ... This occurs because for_each_possible_cpu() returns CPUs even if they are not online. For those CPUs, all_cpu_data[] will be NULL. Since commit 973207ae3d7c ("cpufreq: intel_pstate: Rearrange max frequency updates handling code"), all_cpu_data[] is dereferenced even for CPUs which are not online, causing the NULL pointer dereference. To fix that, pass CPU number to intel_pstate_update_max_freq() and use all_cpu_data[] for those CPUs for which there is a valid cpufreq policy. Fixes: 973207ae3d7c ("cpufreq: intel_pstate: Rearrange max frequency updates handling code") Closes: https://bugzilla.kernel.org/show_bug.cgi?id=221068 Signed-off-by: Srinivas Pandruvada Cc: 6.16+ # 6.16+ Link: https://patch.msgid.link/20260225001752.890164-1-srinivas.pandruvada@linux.intel.com Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/intel_pstate.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index bdc37080d319..11c58af41900 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1476,13 +1476,13 @@ static void __intel_pstate_update_max_freq(struct cpufreq_policy *policy, refresh_frequency_limits(policy); } -static bool intel_pstate_update_max_freq(struct cpudata *cpudata) +static bool intel_pstate_update_max_freq(int cpu) { - struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpudata->cpu); + struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu); if (!policy) return false; - __intel_pstate_update_max_freq(policy, cpudata); + __intel_pstate_update_max_freq(policy, all_cpu_data[cpu]); return true; } @@ -1501,7 +1501,7 @@ static void intel_pstate_update_limits_for_all(void) int cpu; for_each_possible_cpu(cpu) - intel_pstate_update_max_freq(all_cpu_data[cpu]); + intel_pstate_update_max_freq(cpu); mutex_lock(&hybrid_capacity_lock); @@ -1910,7 +1910,7 @@ static void intel_pstate_notify_work(struct work_struct *work) struct cpudata *cpudata = container_of(to_delayed_work(work), struct cpudata, hwp_notify_work); - if (intel_pstate_update_max_freq(cpudata)) { + if (intel_pstate_update_max_freq(cpudata->cpu)) { /* * The driver will not be unregistered while this function is * running, so update the capacity without acquiring the driver