Re: [PATCH 2/2 V7] intel_pstate: add kernel parameter to force loading on Sun X86 servers.

[ethan zhao <ethan.zhao@oracle.com>]

Alexey has tested this patch on Lenovo machines. so

Tested-by: Alexey Kodanev <alexey.kodanev@oracle.com>

On 2014/12/4 10:07, Ethan Zhao wrote:
> To force loading on Oracle Sun X86 servers, provide one kernel command line
> parameter
>
>    intel_pstate = ora_force
>
> For those who be aware of the risk of no power capping capabily working and
> try to get better performance with this driver.
>
> Signed-off-by: Ethan Zhao <ethan.zhao@oracle.com>
> ---
>   v2: change to hardware vendor specific naming parameter.
>   v4: refine code and doc.
>   v5&v6: fix a typo in doc.
>   v7: change enum PCC to PPC.
>
>   Documentation/kernel-parameters.txt | 5 +++++
>   drivers/cpufreq/intel_pstate.c      | 6 +++++-
>   2 files changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 479f332..7d0983e 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -1446,6 +1446,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>   		       disable
>   		         Do not enable intel_pstate as the default
>   		         scaling driver for the supported processors
> +		       ora_force
> +			 Force loading intel_pstate on Oracle Sun Servers(X86).
> +			 only for those who be aware of the risk of no power capping
> +			 capability working and try to get better performance with this
> +			 driver.
>   
>   	intremap=	[X86-64, Intel-IOMMU]
>   			on	enable Interrupt Remapping (default)
> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
> index 1bb62ca..2654e13 100644
> --- a/drivers/cpufreq/intel_pstate.c
> +++ b/drivers/cpufreq/intel_pstate.c
> @@ -866,6 +866,7 @@ static struct cpufreq_driver intel_pstate_driver = {
>   };
>   
>   static int __initdata no_load;
> +static unsigned int  ora_force;
>   
>   static int intel_pstate_msrs_not_valid(void)
>   {
> @@ -1003,7 +1004,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
>   			case PSS:
>   				return intel_pstate_no_acpi_pss();
>   			case PPC:
> -				return intel_pstate_has_acpi_ppc();
> +				return intel_pstate_has_acpi_ppc() &&
> +					(!ora_force);
>   			}
>   	}
>   
> @@ -1078,6 +1080,8 @@ static int __init intel_pstate_setup(char *str)
>   
>   	if (!strcmp(str, "disable"))
>   		no_load = 1;
> +	if (!strcmp(str, "ora_force"))
> +		ora_force = 1;
>   	return 0;
>   }
>   early_param("intel_pstate", intel_pstate_setup);