Re: [PATCH] cpufreq: amd-pstate: Fix the inconsistency in max frequency units

From: Gautham R. Shenoy
Date: Mon May 27 2024 - 11:45:42 EST



On Mon, May 27, 2024 at 09:40:21AM -0500, Mario Limonciello wrote:
> On 5/27/2024 00:11, Dhananjay Ugwekar wrote:
> > The nominal frequency in cpudata is maintained in MHz whereas all other
> > frequencies are in KHz. This means we have to convert nominal frequency
> > value to KHz before we do any interaction with other frequency values.
> >
> > In amd_pstate_set_boost(), this conversion from MHz to KHz is missed,
> > fix that.
> >
> > Tested on a AMD Zen4 EPYC server
> >
> > Before:
> > $ cat /sys/devices/system/cpu/cpufreq/policy*/scaling_max_freq | uniq
> > 2151
> > $ cat /sys/devices/system/cpu/cpufreq/policy*/cpuinfo_min_freq | uniq
> > 400000
> > $ cat /sys/devices/system/cpu/cpufreq/policy*/scaling_cur_freq | uniq
> > 2151
> > 409422
> >
> > After:
> > $ cat /sys/devices/system/cpu/cpufreq/policy*/scaling_max_freq | uniq
> > 2151000
> > $ cat /sys/devices/system/cpu/cpufreq/policy*/cpuinfo_min_freq | uniq
> > 400000
> > $ cat /sys/devices/system/cpu/cpufreq/policy*/scaling_cur_freq | uniq
> > 2151000
> > 1799527
> >
>
> Cc: stable@xxxxxxxxxxxxxxx
>
> > Fixes: ec437d71db77 ("cpufreq: amd-pstate: Introduce a new AMD P-State driver to support future processors")
> > Signed-off-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@xxxxxxx>
>
> Acked-by: Mario Limonciello <mario.limonciello@xxxxxxx>

Acked-by: Gautham R. Shenoy <gautham.shenoy@xxxxxxx>

>
> > ---
> > drivers/cpufreq/amd-pstate.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> > index 1b7e82a0ad2e..cde3b91b4422 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -669,7 +669,7 @@ static int amd_pstate_set_boost(struct cpufreq_policy *policy, int state)
> > if (state)
> > policy->cpuinfo.max_freq = cpudata->max_freq;
> > else
> > - policy->cpuinfo.max_freq = cpudata->nominal_freq;
> > + policy->cpuinfo.max_freq = cpudata->nominal_freq * 1000;
> > policy->max = policy->cpuinfo.max_freq;
>