| Message ID | 1415600090-14233-1-git-send-email-vinceh@nvidia.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Monday, November 10, 2014 02:14:50 PM Vince Hsu wrote: > When the user space tries to set scaling_(max|min)_freq through > sysfs, the cpufreq_set_policy() asks other driver's opinions > for the max/min frequencies. Some device drivers, like Tegra > CPU EDP which is not upstreamed yet though, may constrain the > CPU maximum frequency dynamically because of board design. > So if the user space access happens and some driver is capping > the cpu frequency at the same time, the user_policy->(max|min) > is overridden by the capped value, and that's not expected by > the user space. And if the user space is not invoked again, > the CPU will always be capped by the user_policy->(max|min) > even no drivers limit the CPU frequency any more. > > This patch preserves the user specified min/max settings, so that > every time the cpufreq policy is updated, the new max/min can > be re-evaluated correctly based on the user's expection and > the present device drivers' status. > > Signed-off-by: Vince Hsu <vinceh@nvidia.com> > Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Queued up for 3.19, thanks! > --- > v2: added Viresh's Acked-by > > drivers/cpufreq/cpufreq.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c > index 644b54e1e7d1..0721ab352e2a 100644 > --- a/drivers/cpufreq/cpufreq.c > +++ b/drivers/cpufreq/cpufreq.c > @@ -535,7 +535,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, > static ssize_t store_##file_name \ > (struct cpufreq_policy *policy, const char *buf, size_t count) \ > { \ > - int ret; \ > + int ret, temp; \ > struct cpufreq_policy new_policy; \ > \ > ret = cpufreq_get_policy(&new_policy, policy->cpu); \ > @@ -546,8 +546,10 @@ static ssize_t store_##file_name \ > if (ret != 1) \ > return -EINVAL; \ > \ > + temp = new_policy.object; \ > ret = cpufreq_set_policy(policy, &new_policy); \ > - policy->user_policy.object = policy->object; \ > + if (!ret) \ > + policy->user_policy.object = temp; \ > \ > return ret ? ret : count; \ > } >
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 644b54e1e7d1..0721ab352e2a 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -535,7 +535,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, static ssize_t store_##file_name \ (struct cpufreq_policy *policy, const char *buf, size_t count) \ { \ - int ret; \ + int ret, temp; \ struct cpufreq_policy new_policy; \ \ ret = cpufreq_get_policy(&new_policy, policy->cpu); \ @@ -546,8 +546,10 @@ static ssize_t store_##file_name \ if (ret != 1) \ return -EINVAL; \ \ + temp = new_policy.object; \ ret = cpufreq_set_policy(policy, &new_policy); \ - policy->user_policy.object = policy->object; \ + if (!ret) \ + policy->user_policy.object = temp; \ \ return ret ? ret : count; \ }