| Message ID | 1527319008-66663-1-git-send-email-kevin.wangtao@hisilicon.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Delegated to: | Rafael Wysocki |
| Headers | show |
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 ? > + 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>
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> >
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)); \ + new_policy.min = policy->user_policy.min; \ + new_policy.max = policy->user_policy.max; \ \ ret = sscanf(buf, "%u", &new_policy.object); \ if (ret != 1) \
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(+)