Kristen,
Whatever I would like there is a way to load intel_pstate and give
it a try even it does not support all the PM features.
I think 'force' is OK.
Linda,
Do you like it ? if the 'intel_pstate=force' would force the driver
to be loaded on to HP too ?
Thanks,
Ethan
On Fri, Nov 21, 2014 at 5:23 AM, Kristen Carlson Accardi
<kristen@xxxxxxxxxxxxxxx> wrote:
> On Thu, 20 Nov 2014 08:57:34 +0800
> ethan <ethan.kernel@xxxxxxxxx> wrote:
>
>>
>>
>> > 在 2014年11月20日，03:05，Kristen Carlson Accardi <kristen@xxxxxxxxxxxxxxx> 写道：
>> >
>> > On Tue, 18 Nov 2014 17:37:06 +0900
>> > Ethan Zhao <ethan.zhao@xxxxxxxxxx> wrote:
>> >
>> >> Add kernel command line parameter
>> >> intel_pstate = ignore_acpi_ppc
>> >> and module parameter
>> >> ignore_acpi_ppc = 1
>> >> to allow driver to ignore the ACPI _PPC existence even for Sun x86 servers.
>> >> These parameter could be used for debug\test\workaround etc purpose.
>> >>
>> >> Signed-off-by: Ethan Zhao <ethan.zhao@xxxxxxxxxx>
>> >
>> > What if we used a more generic parameter like "force" that would bypass
>> > any vendor specific checks and just load anyway? This way we don't have
>> > to add new parameters everything some new thing shows up that we want to
>> > ignore.
>> >
>> To be honest, I prefer more generic parameter. But to avoid the possible negative affect
>> To another vendors. I back to this way.
>
> Well, your parameter can still impact other vendors as it is. it
> is pretty typical to assume that using a parameter like "force" means
> you know what you are doing and accept the risks. Especially if its
> documented as such.
>
>>
>> Thanks,
>> Ethan
>> >> ---
>> >> Documentation/kernel-parameters.txt | 3 +++
>> >> drivers/cpufreq/intel_pstate.c | 8 +++++++-
>> >> 2 files changed, 10 insertions(+), 1 deletion(-)
>> >>
>> >> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
>> >> index 4c81a86..f502b85 100644
>> >> --- a/Documentation/kernel-parameters.txt
>> >> +++ b/Documentation/kernel-parameters.txt
>> >> @@ -1446,6 +1446,9 @@ 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
>> >> + ignore_acpi_ppc
>> >> + Ignore the existence of ACPI method _PPC for Sun x86 servers
>> >> + and load the 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 7c5faea..388387b 100644
>> >> --- a/drivers/cpufreq/intel_pstate.c
>> >> +++ b/drivers/cpufreq/intel_pstate.c
>> >> @@ -870,6 +870,7 @@ static struct cpufreq_driver intel_pstate_driver = {
>> >> };
>> >>
>> >> static int __initdata no_load;
>> >> +static unsigned int ignore_acpi_ppc;
>> >>
>> >> static int intel_pstate_msrs_not_valid(void)
>> >> {
>> >> @@ -990,7 +991,7 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void)
>> >> intel_pstate_no_acpi_pss())
>> >> return true;
>> >> if (!strncmp(hdr.oem_id, v_info->oem_id, ACPI_OEM_ID_SIZE) &&
>> >> - intel_pstate_has_acpi_ppc())
>> >> + intel_pstate_has_acpi_ppc() && !ignore_acpi_ppc)
>> >> return true;
>> >> }
>> >>
>> >> @@ -1066,11 +1067,16 @@ static int __init intel_pstate_setup(char *str)
>> >>
>> >> if (!strcmp(str, "disable"))
>> >> no_load = 1;
>> >> + if (!strcmp(str, "ignore_acpi_ppc"))
>> >> + ignore_acpi_ppc = 1;
>> >> return 0;
>> >> }
>> >> early_param("intel_pstate", intel_pstate_setup);
>> >> #endif
>> >>
>> >> +module_param(ignore_acpi_ppc, uint, 0644);
>> >> +MODULE_PARM_DESC(ignore_acpi_ppc,
>> >> + "value 0 or non-zero. non-zero -> ignore ACPI _PPC and load this driver");
>> >> MODULE_AUTHOR("Dirk Brandewie <dirk.j.brandewie@xxxxxxxxx>");
>> >> MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors");
>> >> MODULE_LICENSE("GPL");
>> >
>
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