Re: [PATCH] cpufreq/amd-pstate: Fix setting scaling max/min freq values

From: Dan Martins
Date: Mon Jan 22 2024 - 18:53:24 EST


On Friday, January 19, 2024 6:33:19 A.M. EST Mario Limonciello wrote:
> Scaling min/max freq values were being cached and lagging a setting
> each time. Fix the ordering of the clamp call to ensure they work.
>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217931
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: wkarny@xxxxxxxxx
> Fixes: febab20caeba ("cpufreq/amd-pstate: Fix scaling_min_freq and
> scaling_max_freq update") Signed-off-by: Mario Limonciello
> <mario.limonciello@xxxxxxx>
> ---
> drivers/cpufreq/amd-pstate.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index 1f6186475715..1791d37fbc53 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1232,14 +1232,13 @@ static void amd_pstate_epp_update_limit(struct
> cpufreq_policy *policy) max_limit_perf = div_u64(policy->max *
> cpudata->highest_perf, cpudata->max_freq); min_limit_perf =
> div_u64(policy->min * cpudata->highest_perf, cpudata->max_freq);
>
> + WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
> + WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
> +
> max_perf = clamp_t(unsigned long, max_perf, cpudata-
>min_limit_perf,
> cpudata->max_limit_perf);
> min_perf = clamp_t(unsigned long, min_perf, cpudata-
>min_limit_perf,
> cpudata->max_limit_perf);
> -
> - WRITE_ONCE(cpudata->max_limit_perf, max_limit_perf);
> - WRITE_ONCE(cpudata->min_limit_perf, min_limit_perf);
> -
> value = READ_ONCE(cpudata->cppc_req_cached);
>
> if (cpudata->policy == CPUFREQ_POLICY_PERFORMANCE)

Tested-by: Dan Martins <dan.martins@xxxxxxxx>