| Message ID | 1527667007-48226-1-git-send-email-kevin.wangtao@hisilicon.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Wed, May 30, 2018 at 9:56 AM, Kevin Wangtao <kevin.wangtao@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. > > 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> I've applied the v2 with modified subject and changelog and with the ACK from Viresh. Thanks!
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index b79c532..a970113 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -697,6 +697,9 @@ static ssize_t store_##file_name \ struct cpufreq_policy new_policy; \ \ memcpy(&new_policy, policy, sizeof(*policy)); \ + /* Initialized with user_policy to keep consistency */ \ + 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 | 3 +++ 1 file changed, 3 insertions(+)