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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-10 12:48:35 +0100 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-10 23:41:20 +0100 |
commit | b0142d66f4edb8578b7772d6d7ad731836b82ddb (patch) | |
tree | d5e9cfeb7782e390392c0956ed9b12e9744fdd8c | |
parent | cpuidle: use first valid target residency as poll time (diff) | |
download | linux-b0142d66f4edb8578b7772d6d7ad731836b82ddb.tar.xz linux-b0142d66f4edb8578b7772d6d7ad731836b82ddb.zip |
cpuidle: Fix cpuidle_driver_state_disabled()
It turns out that cpuidle_driver_state_disabled() can be called
before registering the cpufreq driver on some platforms, which
was not expected when it was introduced and which leads to a NULL
pointer dereference when trying to walk the CPUs associated with
the given cpuidle driver.
Fix the problem by making cpuidle_driver_state_disabled() check if
the driver's mask of CPUs associated with it is present and to set
CPUIDLE_FLAG_UNUSABLE for the given idle state in the driver's states
list if that is not the case to cause __cpuidle_register_device() to
set CPUIDLE_STATE_DISABLED_BY_DRIVER for that state for all cpuidle
devices registered by it later.
Fixes: cbda56d5fefc ("cpuidle: Introduce cpuidle_driver_state_disabled() for driver quirks")
Reported-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Tested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r-- | drivers/cpuidle/driver.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/cpuidle/driver.c b/drivers/cpuidle/driver.c index c76423aaef4d..ce6a5f80fb83 100644 --- a/drivers/cpuidle/driver.c +++ b/drivers/cpuidle/driver.c @@ -403,6 +403,13 @@ void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, mutex_lock(&cpuidle_lock); + spin_lock(&cpuidle_driver_lock); + + if (!drv->cpumask) { + drv->states[idx].flags |= CPUIDLE_FLAG_UNUSABLE; + goto unlock; + } + for_each_cpu(cpu, drv->cpumask) { struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu); @@ -415,5 +422,8 @@ void cpuidle_driver_state_disabled(struct cpuidle_driver *drv, int idx, dev->states_usage[idx].disable &= ~CPUIDLE_STATE_DISABLED_BY_DRIVER; } +unlock: + spin_unlock(&cpuidle_driver_lock); + mutex_unlock(&cpuidle_lock); } |