Re: [PATCH v4 19/19] cpufreq/amd-pstate: Drop amd_pstate_epp_cpu_offline()

[Mario Limonciello]

On 2/24/2025 03:25, Dhananjay Ugwekar wrote:
> On 2/20/2025 2:33 AM, Mario Limonciello wrote:
> > From: Mario Limonciello <mario.limonciello@xxxxxxx>
> >
> > When the CPU goes offline there is no need to change the CPPC request
> > because the CPU will go into the deepest C-state it supports already.>
> > Actually changing the CPPC request when it goes offline messes up the
> > cached values and can lead to the wrong values being restored when
> > it comes back.
> >
> > Instead if the CPU comes back online let amd_pstate_epp_set_policy()
> > restore it to expected values.
>
> Small suggestion below, apart from that LGTM
>
> Reviewed-by: Dhananjay Ugwekar <dhananjay.ugwekar@xxxxxxx>

Thanks!

> > Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> > ---
> >   drivers/cpufreq/amd-pstate.c | 9 +--------
> >   1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> > index 408e63aff377a..5068778c1542a 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -1610,14 +1610,7 @@ static int amd_pstate_epp_cpu_online(struct cpufreq_policy *policy)
> >   
> >   static int amd_pstate_epp_cpu_offline(struct cpufreq_policy *policy)
> >   {
> > -	struct amd_cpudata *cpudata = policy->driver_data;
> > -	union perf_cached perf = READ_ONCE(cpudata->perf);
> > -
> > -	if (cpudata->suspended)
> > -		return 0;
> > -
> > -	return amd_pstate_update_perf(policy, perf.lowest_perf, 0, perf.lowest_perf,
> > -				      AMD_CPPC_EPP_BALANCE_POWERSAVE, false);
> > +	return 0;
>
> Instead of making it an empty "return 0" function, can we remove this
> callback altogether? Didnt check if there are any constraints against
> removing it.
I originally had tried removing it, but the driver won't be able to 
setup properly unless the callback is setup.