thermal: cpufreq_cooling: freq_qos_update_request() returns < 0 on error
authorViresh Kumar <viresh.kumar@linaro.org>
Wed, 17 Feb 2021 05:48:58 +0000 (11:18 +0530)
committerDaniel Lezcano <daniel.lezcano@linaro.org>
Wed, 17 Feb 2021 17:53:19 +0000 (18:53 +0100)
commita51afb13311cd85b2f638c691b2734622277d8f5
treebc31c4757f28e409db5bc0f96115f2ab8305a029
parent74369d041a0a3e9e57de50efd4bd4bc10564e254
thermal: cpufreq_cooling: freq_qos_update_request() returns < 0 on error

freq_qos_update_request() returns 1 if the effective constraint value
has changed, 0 if the effective constraint value has not changed, or a
negative error code on failures.

The frequency constraints for CPUs can be set by different parts of the
kernel. If the maximum frequency constraint set by other parts of the
kernel are set at a lower value than the one corresponding to cooling
state 0, then we will never be able to cool down the system as
freq_qos_update_request() will keep on returning 0 and we will skip
updating cpufreq_state and thermal pressure.

Fix that by doing the updates even in the case where
freq_qos_update_request() returns 0, as we have effectively set the
constraint to a new value even if the consolidated value of the
actual constraint is unchanged because of external factors.

Cc: v5.7+ <stable@vger.kernel.org> # v5.7+
Reported-by: Thara Gopinath <thara.gopinath@linaro.org>
Fixes: f12e4f66ab6a ("thermal/cpu-cooling: Update thermal pressure in case of a maximum frequency capping")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Thara Gopinath<thara.gopinath@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/b2b7e84944937390256669df5a48ce5abba0c1ef.1613540713.git.viresh.kumar@linaro.org
drivers/thermal/cpufreq_cooling.c