On Thu, May 24, 2018 at 8:43 AM, Kevin Wangtao <kevin.wang...@hisilicon.com> 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.
How do you reproduce this, exactly? > 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.wang...@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..8b33e08 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)); \ > + new_policy->min = policy->user_policy.min; \ > + new_policy->max = policy->user_policy.max; \ It looks like you haven't even tried to build this, have you? > \ > ret = sscanf(buf, "%u", &new_policy.object); \ > if (ret != 1) \ > -- > 2.8.1 >
