From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ashwin Chaugule Subject: Re: [PATCH v7 2/8] ACPI: Split out ACPI PSS from ACPI Processor driver Date: Mon, 3 Aug 2015 13:24:20 -0400 Message-ID: References: <09d1b5cf25ed3117b9e1b8feeb40ddf801557039.1436464513.git.ashwin.chaugule@linaro.org> <3655608.oFpclyKJ6p@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <3655608.oFpclyKJ6p@vostro.rjw.lan> Sender: linux-pm-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Jaswinder Singh , "linux-pm@vger.kernel.org" , linux acpi , Linaro ACPI Mailman List , Patch Tracking , Viresh Kumar , Sudeep Holla List-Id: linux-acpi@vger.kernel.org On 17 July 2015 at 20:01, Rafael J. Wysocki wrote: > On Thursday, July 09, 2015 02:04:18 PM Ashwin Chaugule wrote: >> The ACPI processor driver is currently tied too closely >> to the ACPI P-states (PSS) and other related constructs >> for controlling CPU performance. >> >> The newer ACPI specification (v5.1 onwards) introduces >> alternative methods to PSS. These new mechanisms are >> described within each ACPI Processor object and so they >> need to be scanned whenever a new Processor object is detected. >> This patch introduces a new Kconfig symbol to allow for >> finer configurability among the two options for controlling >> performance states. There is no change in functionality and >> the option is auto-selected by the architecture Kconfig files. >> >> The following patchwork introduces CPPC: A newer method of >> controlling CPU performance. The OS is not expected to support >> CPPC and PSS at runtime. So the kconfig option lets us make >> these two mutually exclusive at compile time. >> >> Signed-off-by: Ashwin Chaugule >> --- >> arch/x86/Kconfig | 1 + >> drivers/acpi/Kconfig | 19 ++++++--- >> drivers/acpi/Makefile | 6 +-- >> drivers/acpi/processor_driver.c | 86 +++++++++++++++++++++++++------------ >> drivers/cpufreq/Kconfig | 2 +- >> drivers/cpufreq/Kconfig.x86 | 2 + >> include/acpi/processor.h | 94 +++++++++++++++++++++++++++-------------- >> 7 files changed, 142 insertions(+), 68 deletions(-) >> >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 226d569..93d150d 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -143,6 +143,7 @@ config X86 >> select ACPI_LEGACY_TABLES_LOOKUP if ACPI >> select X86_FEATURE_NAMES if PROC_FS >> select SRCU >> + select ACPI_CPU_FREQ_PSS if ACPI >> >> config INSTRUCTION_DECODER >> def_bool y >> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig >> index ab2cbb5..00748dc 100644 >> --- a/drivers/acpi/Kconfig >> +++ b/drivers/acpi/Kconfig >> @@ -166,17 +166,26 @@ config ACPI_DOCK >> This driver supports ACPI-controlled docking stations and removable >> drive bays such as the IBM Ultrabay and the Dell Module Bay. >> >> +config ACPI_CPU_FREQ_PSS >> + bool >> + depends on ACPI_PROCESSOR && CPU_FREQ >> + select THERMAL >> + help >> + This driver implements ACPI methods for controlling CPU performance >> + using PSS methods as described in the ACPI spec. It also enables support >> + for ACPI based performance throttling (TSS) and ACPI based thermal >> + monitoring. It is required by several flavors of cpufreq >> + performance-state drivers. > > So are you not agreeing with what I've said for a few times already or are you > just not listening? > > This option should *not* be user-selectable. So please drop the help part > and make it look like ACPI_SLEEP, for example. Fine. I followed some other examples in the kernel. As long as there is no text after the 'bool', it doesn't show up as a user configurable option in the menuconfig. Having some help text even in such cases seemed helpful to me. Thanks, Ashwin.