| Message ID | 8030961ef762018fc286e4d3d3a010638e900e53.1549955027.git.viresh.kumar@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | [V2,1/2] cpufreq: Allow light-weight tear down and bring up of CPUs | expand |
On 12-02-19, 10:43, Rafael J. Wysocki wrote: > On Tue, Feb 12, 2019 at 8:07 AM Viresh Kumar <viresh.kumar@linaro.org> wrote: > > > > Implement the light-weight tear down and bring up helpers to reduce the > > amount of work to do on CPU offline/online operation. > > > > Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> > > --- > > drivers/cpufreq/cpufreq-dt.c | 17 +++++++++++++++++ > > 1 file changed, 17 insertions(+) > > > > diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c > > index 7ba392911cd0..1aefaa1b0ca2 100644 > > --- a/drivers/cpufreq/cpufreq-dt.c > > +++ b/drivers/cpufreq/cpufreq-dt.c > > @@ -295,6 +295,21 @@ static int cpufreq_init(struct cpufreq_policy *policy) > > return ret; > > } > > > > +static int cpufreq_online(struct cpufreq_policy *policy) > > +{ > > + /* We did light-weight tear down earlier, nothing to do here */ > > + return 0; > > +} > > I think you could avoid having to add this empty stub if the core > checked for both online and offline, that is > > if (driver->offline || driver->online) { This doesn't look great as all we should care about here is ->online() and checking for offline as well looks a bit hacky. > ret = driver->online ? driver->online(policy) : 0; > } else { > ret = driver->init(policy); > } > > or similar. I also thought of a new flag like: CPUFREQ_LIGHT_WEIGHT_OFFLINE and then we can get rid of both online/offline dummies but then thought of starting with the dummy routines to begin with :) -- viresh
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c index 7ba392911cd0..1aefaa1b0ca2 100644 --- a/drivers/cpufreq/cpufreq-dt.c +++ b/drivers/cpufreq/cpufreq-dt.c @@ -295,6 +295,21 @@ static int cpufreq_init(struct cpufreq_policy *policy) return ret; } +static int cpufreq_online(struct cpufreq_policy *policy) +{ + /* We did light-weight tear down earlier, nothing to do here */ + return 0; +} + +static int cpufreq_offline(struct cpufreq_policy *policy) +{ + /* + * Preserve policy->driver_data and don't free resources on light-weight + * tear down. + */ + return 0; +} + static int cpufreq_exit(struct cpufreq_policy *policy) { struct private_data *priv = policy->driver_data; @@ -319,6 +334,8 @@ static struct cpufreq_driver dt_cpufreq_driver = { .get = cpufreq_generic_get, .init = cpufreq_init, .exit = cpufreq_exit, + .online = cpufreq_online, + .offline = cpufreq_offline, .name = "cpufreq-dt", .attr = cpufreq_dt_attr, .suspend = cpufreq_generic_suspend,
Implement the light-weight tear down and bring up helpers to reduce the amount of work to do on CPU offline/online operation. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> --- drivers/cpufreq/cpufreq-dt.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) -- 2.20.1.321.g9e740568ce00