Re: [PATCH] amd-pstate-ut: Reset amd-pstate driver mode after running selftests

[Mario Limonciello <mario.limonciello@amd.com>]

On 4/30/2025 1:42 AM, Swapnil Sapkal wrote:
> In amd-pstate-ut, one of the basic test is to switch between all
> possible mode combinations. After running this test the mode of the
> amd-pstate driver is active mode. Store and reset the mode to its original
> state.
> 
> Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
> Signed-off-by: Swapnil Sapkal <swapnil.sapkal@amd.com>

Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>

> ---
>   drivers/cpufreq/amd-pstate-ut.c | 19 ++++++++++++-------
>   drivers/cpufreq/amd-pstate.c    |  6 ++++++
>   drivers/cpufreq/amd-pstate.h    |  1 +
>   3 files changed, 19 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate-ut.c b/drivers/cpufreq/amd-pstate-ut.c
> index e671bc7d1550..30835d0e4994 100644
> --- a/drivers/cpufreq/amd-pstate-ut.c
> +++ b/drivers/cpufreq/amd-pstate-ut.c
> @@ -242,6 +242,8 @@ static int amd_pstate_set_mode(enum amd_pstate_mode mode)
>   static int amd_pstate_ut_check_driver(u32 index)
>   {
>   	enum amd_pstate_mode mode1, mode2 = AMD_PSTATE_DISABLE;
> +	enum amd_pstate_mode orig_mode = amd_pstate_get_status();
> +	int ret;
>   
>   	for (mode1 = AMD_PSTATE_DISABLE; mode1 < AMD_PSTATE_MAX; mode1++) {
>   		int ret = amd_pstate_set_mode(mode1);
> @@ -251,16 +253,19 @@ static int amd_pstate_ut_check_driver(u32 index)
>   			if (mode1 == mode2)
>   				continue;
>   			ret = amd_pstate_set_mode(mode2);
> -			if (ret) {
> -				pr_err("%s: failed to update status for %s->%s\n", __func__,
> -					amd_pstate_get_mode_string(mode1),
> -					amd_pstate_get_mode_string(mode2));
> -				return ret;
> -			}
> +			if (ret)
> +				goto out;
>   		}
>   	}
>   
> -	return 0;
> +out:
> +	if (ret)
> +		pr_warn("%s: failed to update status for %s->%s: %d\n", __func__,
> +			amd_pstate_get_mode_string(mode1),
> +			amd_pstate_get_mode_string(mode2), ret);
> +
> +	amd_pstate_set_mode(orig_mode);
> +	return ret;
>   }
>   
>   static int __init amd_pstate_ut_init(void)
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index b961f3a3b580..af08049fe96f 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -1305,6 +1305,12 @@ static ssize_t amd_pstate_show_status(char *buf)
>   	return sysfs_emit(buf, "%s\n", amd_pstate_mode_string[cppc_state]);
>   }
>   
> +int amd_pstate_get_status(void)
> +{
> +	return cppc_state;
> +}
> +EXPORT_SYMBOL_GPL(amd_pstate_get_status);
> +
>   int amd_pstate_update_status(const char *buf, size_t size)
>   {
>   	int mode_idx;
> diff --git a/drivers/cpufreq/amd-pstate.h b/drivers/cpufreq/amd-pstate.h
> index fbe1c08d3f06..512d5d97806e 100644
> --- a/drivers/cpufreq/amd-pstate.h
> +++ b/drivers/cpufreq/amd-pstate.h
> @@ -119,6 +119,7 @@ enum amd_pstate_mode {
>   	AMD_PSTATE_MAX,
>   };
>   const char *amd_pstate_get_mode_string(enum amd_pstate_mode mode);
> +int amd_pstate_get_status(void);
>   int amd_pstate_update_status(const char *buf, size_t size);
>   
>   #endif /* _LINUX_AMD_PSTATE_H */