Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757587AbaKUDHY (ORCPT ); Thu, 20 Nov 2014 22:07:24 -0500 Received: from mail-qg0-f46.google.com ([209.85.192.46]:47028 "EHLO mail-qg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757301AbaKUDHU convert rfc822-to-8bit (ORCPT ); Thu, 20 Nov 2014 22:07:20 -0500 MIME-Version: 1.0 In-Reply-To: <20141120132317.00ad7210@kcaccard-desk.amr.corp.intel.com> References: <1416299826-15813-1-git-send-email-ethan.zhao@oracle.com> <1416299826-15813-8-git-send-email-ethan.zhao@oracle.com> <20141119110548.24a0a808@kcaccard-desk.amr.corp.intel.com> <41ADCDB8-C204-4661-833B-F68E7D687B61@gmail.com> <20141120132317.00ad7210@kcaccard-desk.amr.corp.intel.com> Date: Fri, 21 Nov 2014 11:07:19 +0800 Message-ID: Subject: Re: [PATCH 3/3] intel_pstate: add module and kernel command line parameter to ignore ACPI _PPC From: Ethan Zhao To: Kristen Carlson Accardi Cc: Ethan Zhao , "" , "" , "" , "" , "" , "" , "" , "" , "" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 wrote: > On Thu, 20 Nov 2014 08:57:34 +0800 > ethan wrote: > >> >> >> > 在 2014年11月20日，03:05，Kristen Carlson Accardi 写道： >> > >> > On Tue, 18 Nov 2014 17:37:06 +0900 >> > Ethan Zhao 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 >> > >> > 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 "); >> >> MODULE_DESCRIPTION("'intel_pstate' - P state driver Intel Core processors"); >> >> MODULE_LICENSE("GPL"); >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/