Messages in this thread | | | Subject | Re: [PATCH V2] cpufreq: reinitialize new policy min/max when writing scaling_(max|min)_freq | From | "Wangtao (Kevin, Kirin)" <> | Date | Wed, 30 May 2018 16:03:37 +0800 |
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在 2018/5/29 18:26, Viresh Kumar 写道: > On 26-05-18, 15:16, Kevin Wangtao wrote: >> consider such situation, current user_policy.min is 1000000, >> current user_policy.max is 1200000, in cpufreq_set_policy, >> other driver may update policy.min to 1200000, policy.max to >> 1300000. After that, If we input "echo 1300000 > scaling_min_freq", >> then user_policy.min will be 1300000, and user_policy.max is >> still 1200000, because the input value is checked with policy.max >> not user_policy.max. if we get all related cpus offline and >> online again, it will cause cpufreq_init_policy fail because >> user_policy.min is higher than user_policy.max. >> >> The solution is when user space tries to write scaling_(max|min)_freq, >> the min/max of new_policy should be reinitialized with min/max >> of user_policy, like what cpufreq_update_policy does. >> >> Signed-off-by: Kevin Wangtao <kevin.wangtao@hisilicon.com> >> --- >> drivers/cpufreq/cpufreq.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c >> index b79c532..82123a1 100644 >> --- a/drivers/cpufreq/cpufreq.c >> +++ b/drivers/cpufreq/cpufreq.c >> @@ -697,6 +697,8 @@ static ssize_t store_##file_name \ >> struct cpufreq_policy new_policy; \ >> \ >> memcpy(&new_policy, policy, sizeof(*policy)); \ > > Maybe add a comment here on why this is required ? OK > >> + new_policy.min = policy->user_policy.min; \ >> + new_policy.max = policy->user_policy.max; \ >> \ >> ret = sscanf(buf, "%u", &new_policy.object); \ >> if (ret != 1) \ > > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> >
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