cpufreq: Skip cpufreq resume if it's not suspended
cpufreq_resume can be called even without preceding cpufreq_suspend. This can happen in following scenario: suspend_devices_and_enter --> dpm_suspend_start --> dpm_prepare --> device_prepare : this function errors out --> dpm_suspend: this is skipped due to dpm_prepare failure this means cpufreq_suspend is skipped over --> goto Recover_platform, due to previous error --> goto Resume_devices --> dpm_resume_end --> dpm_resume --> cpufreq_resume In case schedutil is used as frequency governor, cpufreq_resume will eventually call sugov_start, which does following: memset(sg_cpu, 0, sizeof(*sg_cpu)); .... This effectively erases function pointer for frequency update, causing crash later on. The function pointer would have been set correctly if subsequent cpufreq_add_update_util_hook runs successfully, but that function returns earlier because cpufreq_suspend was not called: if (WARN_ON(per_cpu(cpufreq_update_util_data, cpu))) return; The fix is to check cpufreq_suspended first, if it's false, that means cpufreq_suspend was not called in the first place, so do not resume cpufreq. Signed-off-by: Bo Yan <byan@nvidia.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw: Dropped printing a message ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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@ -1686,6 +1686,9 @@ void cpufreq_resume(void)
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if (!cpufreq_driver)
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return;
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if (unlikely(!cpufreq_suspended))
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return;
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cpufreq_suspended = false;
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if (!has_target() && !cpufreq_driver->resume)
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