From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Brandewie Subject: Re: [PATCH 2/2 v3] intel_pstate: add kernel parameter to enable loading on Sun X86 servers. Date: Tue, 25 Nov 2014 06:51:35 -0800 Message-ID: <54749777.7020802@intel.com> References: <1416891578-14171-1-git-send-email-ethan.zhao@oracle.com> <1416891578-14171-3-git-send-email-ethan.zhao@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1416891578-14171-3-git-send-email-ethan.zhao@oracle.com> Sender: linux-doc-owner@vger.kernel.org To: Ethan Zhao , linda.knippers@hp.com, viresh.kumar@linaro.org, rjw@rjwysocki.net, corbet@lwn.net Cc: dirk.j.brandewie@intel.com, linux-doc@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, ethan.kernel@gmail.com List-Id: linux-pm@vger.kernel.org On 11/24/2014 08:59 PM, Ethan Zhao wrote: > To force loading on Oracle Sun X86 servers, provide one kernel command line > parameter > > intel_pstate = onora > > For those who be aware of the risk doing so. > > Signed-off-by: Ethan Zhao > --- > v2: change to hardware vendor specific naming parameter. > > Documentation/kernel-parameters.txt | 3 +++ > drivers/cpufreq/intel_pstate.c | 6 +++++- > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt > index 479f332..e4b1b81 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 > + onora > + Enable loading intel_pstate on Oracle Sun Servers(X86). > + only for those who be aware of the risk. What are the risks? What is the behaviour if platform power management is enabled and intel_pstate is trying to control P state selection as well? If intel_pstate will be able to successfully control P state selection with platform power management enabled then how about the name "oracle_force"? Also the documentation should say what the risks are. > > 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 fa67fb3..e49b050 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 load_on_sun; > > static int intel_pstate_msrs_not_valid(void) > { > @@ -1005,7 +1006,8 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void) > 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_has_acpi_ppc()) > + intel_pstate_has_acpi_ppc() && > + !load_on_sun) > return true; > } > > @@ -1080,6 +1082,8 @@ static int __init intel_pstate_setup(char *str) > > if (!strcmp(str, "disable")) > no_load = 1; > + if (!strcmp(str, "onora")) > + load_on_sun = 1; > return 0; > } > early_param("intel_pstate", intel_pstate_setup); >