Re: [PATCH 1/2 V4] intel_pstate: skip this driver if Sun server has _PPC method

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

(2014/11/28 12:36), Ethan Zhao wrote:
> Oracle Sun X86 servers have dynamic power capping capability that works via
> ACPI _PPC method etc, so skip loading this driver if Sun server has ACPI _PPC
> enabled.
> 
> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
> Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>
> Tested-by: Linda Knippers <linda.knippers@hp.com>
> ---
>    v2: fix break HP Proliant issue.
>    v3: expand the hardware vendor list.
>    v4: refine code.
> 
>   drivers/cpufreq/intel_pstate.c | 45 ++++++++++++++++++++++++++++++++++++++----
>   1 file changed, 41 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 27bb6d3..1bb62ca 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -943,15 +943,46 @@ static bool intel_pstate_no_acpi_pss(void)
>   	return true;
>   }
>   
> +static bool intel_pstate_has_acpi_ppc(void)
> +{
> +	int i;
> +
> +	for_each_possible_cpu(i) {
> +		struct acpi_processor *pr = per_cpu(processors, i);
> +
> +		if (!pr)
> +			continue;
> +		if (acpi_has_method(pr->handle, "_PPC"))
> +			return true;
> +	}
> +	return false;
> +}
> +

> +enum {
> +	PSS,
> +	PCC,
> +};

What does PCC stand for? Is it PPC?

Thanks,
Yasuaki Ishimatsu

> +
>   struct hw_vendor_info {
>   	u16  valid;
>   	char oem_id[ACPI_OEM_ID_SIZE];
>   	char oem_table_id[ACPI_OEM_TABLE_ID_SIZE];
> +	int  oem_pwr_table;
>   };
>   
>   /* Hardware vendor-specific info that has its own power management modes */
>   static struct hw_vendor_info vendor_info[] = {
> -	{1, "HP    ", "ProLiant"},
> +	{1, "HP    ", "ProLiant", PSS},
> +	{1, "ORACLE", "X4-2    ", PCC},
> +	{1, "ORACLE", "X4-2L   ", PCC},
> +	{1, "ORACLE", "X4-2B   ", PCC},
> +	{1, "ORACLE", "X3-2    ", PCC},
> +	{1, "ORACLE", "X3-2L   ", PCC},
> +	{1, "ORACLE", "X3-2B   ", PCC},
> +	{1, "ORACLE", "X4470M2 ", PCC},
> +	{1, "ORACLE", "X4270M3 ", PCC},
> +	{1, "ORACLE", "X4270M2 ", PCC},
> +	{1, "ORACLE", "X4170M2 ", PCC},
>   	{0, "", ""},
>   };
>   
> @@ -966,15 +997,21 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
>   
>   	for (v_info = vendor_info; v_info->valid; v_info++) {
>   		if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
> -		    !strncmp(hdr.oem_table_id, v_info->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
> -		    intel_pstate_no_acpi_pss())
> -			return true;
> +			!strncmp(hdr.oem_table_id, v_info->oem_table_id,
> +						ACPI_OEM_TABLE_ID_SIZE))
> +			switch (v_info->oem_pwr_table) {
> +			case PSS:
> +				return intel_pstate_no_acpi_pss();
> +			case PCC:
> +				return intel_pstate_has_acpi_ppc();
> +			}
>   	}
>   
>   	return false;
>   }
>   #else /* CONFIG_ACPI not enabled */
>   static inline bool intel_pstate_platform_pwr_mgmt_exists(void) { return false; }
> +static inline bool intel_pstate_has_acpi_ppc(void) { return false; }
>   #endif /* CONFIG_ACPI */
>   
>   static int __init intel_pstate_init(void)
>