2023-11-23 08:28:56

by Gautham R. Shenoy

[permalink] [raw]
Subject: [PATCH] cpufreq/amd-pstate: Fix the return value of amd_pstate_fast_switch()

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")
Signed-off-by: Gautham R. Shenoy <[email protected]>
---
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


2023-11-23 08:54:39

by Yuan, Perry

[permalink] [raw]
Subject: RE: [PATCH] cpufreq/amd-pstate: Fix the return value of amd_pstate_fast_switch()

[AMD Official Use Only - General]

> -----Original Message-----
> From: Shenoy, Gautham Ranjal <[email protected]>
> Sent: Thursday, November 23, 2023 4:28 PM
> To: Karny, Wyes <[email protected]>; Huang, Ray
> <[email protected]>; Limonciello, Mario <[email protected]>;
> Yuan, Perry <[email protected]>; Rafael J . Wysocki <[email protected]>;
> Viresh Kumar <[email protected]>
> Cc: [email protected]; [email protected]; Shenoy, Gautham
> Ranjal <[email protected]>
> Subject: [PATCH] cpufreq/amd-pstate: Fix the return value of
> amd_pstate_fast_switch()
>
> 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")
> Signed-off-by: Gautham R. Shenoy <[email protected]>
> ---
> 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

LGTM
Thank you for the fix.

Reviewed-by: Perry Yuan <[email protected]>

2023-11-24 04:24:27

by Wyes Karny

[permalink] [raw]
Subject: Re: [PATCH] cpufreq/amd-pstate: Fix the return value of amd_pstate_fast_switch()

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 <[email protected]>

> Signed-off-by: Gautham R. Shenoy <[email protected]>
> ---
> 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
>

2023-11-24 07:32:28

by Huang Rui

[permalink] [raw]
Subject: Re: [PATCH] cpufreq/amd-pstate: Fix the return value of amd_pstate_fast_switch()

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 <[email protected]>
>

Acked-by: Huang Rui <[email protected]>

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

Thanks,
Ray

> > Signed-off-by: Gautham R. Shenoy <[email protected]>
> > ---
> > 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
> >

2023-11-24 10:25:55

by Gautham R. Shenoy

[permalink] [raw]
Subject: Re: [PATCH] cpufreq/amd-pstate: Fix the return value of amd_pstate_fast_switch()

On Fri, Nov 24, 2023 at 03:31:34PM +0800, Huang Rui wrote:
> 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 <[email protected]>
> >
>
> Acked-by: Huang Rui <[email protected]>

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

Yes, I forgot to do that. I will send a v2 having collected your
Acked-by and the Reviewed-by's from Perry and Wyes.

>
> Thanks,
> Ray

--
Thanks and Regards
gautham.