From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dirk Brandewie Subject: Re: [PATCH 1/3] intel_pstate: skip the driver if Sun server has ACPI _PPC method Date: Thu, 20 Nov 2014 08:50:06 -0800 Message-ID: <546E1BBE.7050906@intel.com> References: <1416299826-15813-1-git-send-email-ethan.zhao@oracle.com> <1416299826-15813-2-git-send-email-ethan.zhao@oracle.com> <546CFBEE.6090103@hp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <546CFBEE.6090103@hp.com> Sender: linux-doc-owner@vger.kernel.org To: Linda Knippers , Ethan Zhao , viresh.kumar@linaro.org, rjw@rjwysocki.net, corbet@lwn.net Cc: dirk.j.brandewie@intel.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, ethan.kernel@gmail.com, joe.jin@oracle.com, brian.maly@oracle.com List-Id: linux-pm@vger.kernel.org On 11/19/2014 12:22 PM, Linda Knippers wrote: > On 11/18/2014 3:37 AM, 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 >> --- >> drivers/cpufreq/intel_pstate.c | 20 ++++++++++++++++++++ >> 1 file changed, 20 insertions(+) >> >> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c >> index 27bb6d3..5498eb0 100644 >> --- a/drivers/cpufreq/intel_pstate.c >> +++ b/drivers/cpufreq/intel_pstate.c >> @@ -943,6 +943,21 @@ 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; >> +} >> + >> struct hw_vendor_info { >> u16 valid; >> char oem_id[ACPI_OEM_ID_SIZE]; >> @@ -952,6 +967,7 @@ struct hw_vendor_info { >> /* Hardware vendor-specific info that has its own power management modes */ >> static struct hw_vendor_info vendor_info[] = { >> {1, "HP ", "ProLiant"}, >> + {1, "ORACLE", ""}, >> {0, "", ""}, >> }; >> >> @@ -969,12 +985,16 @@ static bool intel_pstate_platform_pwr_mgmt_exists(void) >> !strncmp(hdr.oem_table_id, v_info->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) && >> 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()) > > We need try this on a few platforms to make sure this patch doesn't break the > HP platforms that may or may not need this driver, depending on the BIOS settings. > It looks like HP systems would get swept up in this check too if they have _PPC What about extending the hw_vendor_info struct to include whether _PSS or _PPC should be done for the platform since it appears that oracle and HP have implemented similar functionality using two different methods. > I don't suppose you tested on a ProLiant too? > > -- ljk > >> + return true; >> } >> >> 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) >> >