Re: [PATCH] cpufreq: Add CPU frequency policy change notification support

[Tony W Wang-oc]

On 2026/1/21 13:51, Viresh Kumar wrote:
> On 20-01-26, 17:24, Tony W Wang-oc wrote:
> > Implemented CPUFREQ_CHANGE_POLICY notification in cpufreq subsystem.
> > This enhancement allows kernel modules to be notified when a CPU frequency
> > policy is modified, facilitating more integrated system management.
> > The notification is dispatched after a successful governor switch during
> > policy updates.
> >
> > Signed-off-by: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx>
> > ---
> >   drivers/cpufreq/cpufreq.c | 2 ++
> >   include/linux/cpufreq.h   | 1 +
> >   2 files changed, 3 insertions(+)
>
> Who is using this stuff ? Please explain why you need this and how you
> are going to use it. I don't think it is a great idea, but I still
> want to see what you are doing in the first place.

The expectation is to register a notifier of type 
CPUFREQ_POLICY_NOTIFIER via cpufreq_register_notifier in one of our 
drivers. The notifier callback will configure Zhaoxin registers to 
different values based on the different cpufreq governors when the event 
is CPUFREQ_GOVERNOR_CHANGE, thereby allowing the Zhaoxin hardware to 
adopt different power management strategies.

Sincerely!
TonyWWang-oc