On Wed, Feb 17, 2021 at 6:50 AM Viresh Kumar <[email protected]> wrote: > > 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+ <[email protected]> # v5.7+ > Reported-by: Thara Gopinath <[email protected]> > Fixes: f12e4f66ab6a ("thermal/cpu-cooling: Update thermal pressure in case of > a maximum frequency capping") > Signed-off-by: Viresh Kumar <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]> > --- > Hi Guys, > > This needs to go in 5.12-rc. > > Thara, please give this a try and give your tested-by :). > > drivers/thermal/cpufreq_cooling.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/thermal/cpufreq_cooling.c > b/drivers/thermal/cpufreq_cooling.c > index f5af2571f9b7..10af3341e5ea 100644 > --- a/drivers/thermal/cpufreq_cooling.c > +++ b/drivers/thermal/cpufreq_cooling.c > @@ -485,7 +485,7 @@ static int cpufreq_set_cur_state(struct > thermal_cooling_device *cdev, > frequency = get_state_freq(cpufreq_cdev, state); > > ret = freq_qos_update_request(&cpufreq_cdev->qos_req, frequency); > - if (ret > 0) { > + if (ret >= 0) { > cpufreq_cdev->cpufreq_state = state; > cpus = cpufreq_cdev->policy->cpus; > max_capacity = arch_scale_cpu_capacity(cpumask_first(cpus)); > -- > 2.25.0.rc1.19.g042ed3e048af >
