Re: [PATCH v2 4/9] cpufreq: Add a flag to auto-register a cooling device

From: Stephen Boyd
Date: Mon Jan 14 2019 - 18:57:56 EST


Quoting Amit Kucheria (2019-01-14 02:21:06)
> All cpufreq drivers do similar things to register as a cooling device.
> Provide a cpufreq driver flag so drivers can just ask the cpufreq core
> to register the cooling device on their behalf. This allows us to get
> rid of duplicated code in the drivers.
>
> Suggested-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> Suggested-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
> Signed-off-by: Amit Kucheria <amit.kucheria@xxxxxxxxxx>
> ---
> drivers/cpufreq/cpufreq.c | 13 +++++++++++++
> include/linux/cpufreq.h | 6 ++++++
> 2 files changed, 19 insertions(+)
>
> diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
> index 6f23ebb395f1..7faebfc61e60 100644
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -30,6 +30,7 @@
> #include <linux/syscore_ops.h>
> #include <linux/tick.h>
> #include <trace/events/power.h>
> +#include <linux/cpu_cooling.h>

Maybe this is supposed to be ordered alphabetically? If so, this should
be much higher.

>
> static LIST_HEAD(cpufreq_policy_list);
>
> @@ -1318,6 +1319,12 @@ static int cpufreq_online(unsigned int cpu)
> if (cpufreq_driver->ready)
> cpufreq_driver->ready(policy);
>
> + if (cpufreq_driver->flags & CPUFREQ_AUTO_REGISTER_COOLING_DEV) {
> + struct thermal_cooling_device **cdev = &policy->cooldev;
> +
> + *cdev = of_cpufreq_cooling_register(policy);
> + }

This seems to be some complicated way of writing:

policy->cooldev = of_cpufreq_cooling_register(policy);

?

> +
> pr_debug("initialization complete\n");
>
> return 0;
> @@ -1411,6 +1418,12 @@ static int cpufreq_offline(unsigned int cpu)
> if (has_target())
> cpufreq_exit_governor(policy);
>
> + if (cpufreq_driver->flags & CPUFREQ_AUTO_REGISTER_COOLING_DEV) {
> + struct thermal_cooling_device **cdev = &policy->cooldev;
> +
> + cpufreq_cooling_unregister(*cdev);

Similar? I'm confused!