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

Mario Limonciello
2025-02-25T02:35:16Z

On 2/24/2025 03:25, Dhananjay Ugwekar wrote:
> On 2/20/2025 2:33 AM, Mario Limonciello wrote:
>> From: Mario Limonciello <mario.limonciello@amd.com>
>>
>> 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@amd.com>

Thanks!

>
>>
>> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
>> ---
>> 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.