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Date:   Fri, 24 Nov 2023 15:31:34 +0800
From:   Huang Rui <ray.huang@amd.com>
To:     "Karny, Wyes" <Wyes.Karny@amd.com>,
        "Shenoy, Gautham Ranjal" <gautham.shenoy@amd.com>
Cc:     "Limonciello, Mario" <Mario.Limonciello@amd.com>,
        "Yuan, Perry" <Perry.Yuan@amd.com>,
        "Rafael J . Wysocki" <rafael@kernel.org>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] cpufreq/amd-pstate: Fix the return value of
 amd_pstate_fast_switch()
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References: <20231123082757.3527-1-gautham.shenoy@amd.com>
 <ZWAlXl6MP20khEwB@BLR-5CG13462PL.amd.com>
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On Fri, Nov 24, 2023 at 12:23:58PM +0800, Karny, Wyes wrote:
> On 23 Nov 13:57, Gautham R. Shenoy wrote:
> > cpufreq_driver->fast_switch() callback expects a frequency as a return
> > value. amd_pstate_fast_switch() was returning the return value of
> > amd_pstate_update_freq(), which only indicates a success or failure.
> > 
> > Fix this by making amd_pstate_fast_switch() return the target_freq
> > when the call to amd_pstate_update_freq() is successful, and return
> > the current frequency from policy->cur when the call to
> > amd_pstate_update_freq() is unsuccessful.
> > 
> > Fixes: 4badf2eb1e98 ("cpufreq: amd-pstate: Add ->fast_switch() callback")
> 
> Reviewed-by: Wyes Karny <wyes.karny@amd.com>
> 

Acked-by: Huang Rui <ray.huang@amd.com>

Do you want to cc stable mailing list to fix it in stable kernels?

Thanks,
Ray

> > Signed-off-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> > ---
> >  drivers/cpufreq/amd-pstate.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> > index 9a1e194d5cf8..300f81d36291 100644
> > --- a/drivers/cpufreq/amd-pstate.c
> > +++ b/drivers/cpufreq/amd-pstate.c
> > @@ -518,7 +518,9 @@ static int amd_pstate_target(struct cpufreq_policy *policy,
> >  static unsigned int amd_pstate_fast_switch(struct cpufreq_policy *policy,
> >  				  unsigned int target_freq)
> >  {
> > -	return amd_pstate_update_freq(policy, target_freq, true);
> > +	if (!amd_pstate_update_freq(policy, target_freq, true))
> > +		return target_freq;
> > +	return policy->cur;
> >  }
> >  
> >  static void amd_pstate_adjust_perf(unsigned int cpu,
> > -- 
> > 2.25.1
> >