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

Dhananjay Ugwekar
2025-02-24T09:25:48Z

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>

>
> 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.

> }
>
> static int amd_pstate_epp_suspend(struct cpufreq_policy *policy)