Re: [PATCH v2 5/9] cpufreq/amd-pstate: Remove "amd_dynamic_epp" cmdline and "dynamic_epp" sysfs

[Mario Limonciello <superm1@kernel.org>]

On 7/23/26 15:12, K Prateek Nayak wrote:
> Since dynamic_epp has been converted to an
> "energy_performance_preference", toggling the feature via the sysfs file
> or the kernel cmdline is now redundant.
> 
> Remove the sysfs file and the "amd_dynamic_epp" cmdline and only depend
> on "energy_performance_preference" to toggle dynamic_epp.
> 
> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
> ---
> Changelog rfc v1..v2:
> 
> o Removed "dynamic_epp" gloabal control, the "amd_synamic_epp" cmdline,
>    and the "fdynamic_epp" sysfs since they are all redundant after the
>    rework.
> ---
>   drivers/cpufreq/amd-pstate.c | 55 +-----------------------------------
>   1 file changed, 1 insertion(+), 54 deletions(-)
> 
> diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
> index fc90e4108c22..92da8937df04 100644
> --- a/drivers/cpufreq/amd-pstate.c
> +++ b/drivers/cpufreq/amd-pstate.c
> @@ -87,7 +87,6 @@ static struct cpufreq_driver amd_pstate_driver;
>   static struct cpufreq_driver amd_pstate_epp_driver;
>   static int cppc_state = AMD_PSTATE_UNDEFINED;
>   static bool amd_pstate_prefcore = true;
> -static bool dynamic_epp;
>   static struct quirk_entry *quirks;
>   
>   /*
> @@ -1834,50 +1833,12 @@ static ssize_t prefcore_show(struct device *dev,
>   	return sysfs_emit(buf, "%s\n", str_enabled_disabled(amd_pstate_prefcore));
>   }
>   
> -static ssize_t dynamic_epp_show(struct device *dev,
> -				struct device_attribute *attr, char *buf)
> -{
> -	return sysfs_emit(buf, "%s\n", str_enabled_disabled(dynamic_epp));
> -}
> -
> -static ssize_t dynamic_epp_store(struct device *a, struct device_attribute *b,
> -				 const char *buf, size_t count)
> -{
> -	bool enabled;
> -	int ret;
> -
> -	ret = kstrtobool(buf, &enabled);
> -	if (ret)
> -		return ret;
> -
> -	guard(mutex)(&amd_pstate_driver_lock);
> -
> -	if (cppc_state != AMD_PSTATE_ACTIVE) {
> -		pr_debug("dynamic_epp can only be toggled in active mode\n");
> -		return -EINVAL;
> -	}
> -
> -	/* Nothing to do */
> -	if (dynamic_epp == enabled)
> -		return count;
> -
> -	/* reinitialize with desired dynamic EPP value */
> -	dynamic_epp = enabled;
> -	ret = amd_pstate_change_driver_mode(cppc_state);
> -	if (ret)
> -		dynamic_epp = false;
> -
> -	return ret ? ret : count;
> -}
> -
>   static DEVICE_ATTR_RW(status);
>   static DEVICE_ATTR_RO(prefcore);
> -static DEVICE_ATTR_RW(dynamic_epp);
>   
>   static struct attribute *pstate_global_attributes[] = {
>   	&dev_attr_status.attr,
>   	&dev_attr_prefcore.attr,
> -	&dev_attr_dynamic_epp.attr,
>   	NULL
>   };
>   
> @@ -1984,10 +1945,7 @@ static int amd_pstate_epp_cpu_init(struct cpufreq_policy *policy)
>   		cpudata->current_profile = PLATFORM_PROFILE_BALANCED;
>   	}
>   
> -	if (dynamic_epp)
> -		ret = amd_pstate_set_dynamic_epp(policy);
> -	else
> -		ret = amd_pstate_set_epp(policy, cpudata->epp_default_dc);
> +	ret = amd_pstate_set_epp(policy, cpudata->epp_default_dc);
>   	if (ret)
>   		goto free_cpudata1;
>   
> @@ -2398,19 +2356,8 @@ static int __init amd_prefcore_param(char *str)
>   	return 0;
>   }
>   
> -static int __init amd_dynamic_epp_param(char *str)
> -{
> -	if (!strcmp(str, "disable"))
> -		dynamic_epp = false;
> -	if (!strcmp(str, "enable"))
> -		dynamic_epp = true;
> -
> -	return 0;
> -}
> -
>   early_param("amd_pstate", amd_pstate_param);
>   early_param("amd_prefcore", amd_prefcore_param);
> -early_param("amd_dynamic_epp", amd_dynamic_epp_param);
>   
>   MODULE_AUTHOR("Huang Rui <ray.huang@amd.com>");
>   MODULE_DESCRIPTION("AMD Processor P-state Frequency Driver");