2023-11-27 11:12:26

by Gautham R. Shenoy

Subject: [PATCH v2] 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")
Acked-by: Huang Rui <[email protected]>
Reviewed-by: Wyes Karny <[email protected]>
Reviewed-by: Perry Yuan <[email protected]>
Cc: [email protected] # v6.4+
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

2023-11-28 14:11:20

by Rafael J. Wysocki

Subject: Re: [PATCH v2] cpufreq/amd-pstate: Fix the return value of amd_pstate_fast_switch()

On Mon, Nov 27, 2023 at 12:11 PM Gautham R. Shenoy
<[email protected]> 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")
> Acked-by: Huang Rui <[email protected]>
> Reviewed-by: Wyes Karny <[email protected]>
> Reviewed-by: Perry Yuan <[email protected]>
> Cc: [email protected] # v6.4+
> 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,
> --

Applied as 6.7-rc material, thanks!

BTW, if you are aware of any pending AMD P-state fixes for 6.7, please
let me know.