From 3a53396b0381ec9d5180fd8fe7a681c8ce95fd9a Mon Sep 17 00:00:00 2001 From: ShuoX Liu Date: Wed, 28 Mar 2012 15:19:11 -0700 Subject: cpuidle: add a sysfs entry to disable specific C state for debug purpose. Some C states of new CPU might be not good. One reason is BIOS might configure them incorrectly. To help developers root cause it quickly, the patch adds a new sysfs entry, so developers could disable specific C state manually. In addition, C state might have much impact on performance tuning, as it takes much time to enter/exit C states, which might delay interrupt processing. With the new debug option, developers could check if a deep C state could impact performance and how much impact it could cause. Also add this option in Documentation/cpuidle/sysfs.txt. [akpm@linux-foundation.org: check kstrtol return value] Signed-off-by: ShuoX Liu Reviewed-by: Yanmin Zhang Reviewed-and-Tested-by: Deepthi Dharwar Signed-off-by: Andrew Morton Signed-off-by: Len Brown --- Documentation/cpuidle/sysfs.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation') diff --git a/Documentation/cpuidle/sysfs.txt b/Documentation/cpuidle/sysfs.txt index 50d7b1642759..9d28a3406e74 100644 --- a/Documentation/cpuidle/sysfs.txt +++ b/Documentation/cpuidle/sysfs.txt @@ -36,6 +36,7 @@ drwxr-xr-x 2 root root 0 Feb 8 10:42 state3 /sys/devices/system/cpu/cpu0/cpuidle/state0: total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power @@ -45,6 +46,7 @@ total 0 /sys/devices/system/cpu/cpu0/cpuidle/state1: total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power @@ -54,6 +56,7 @@ total 0 /sys/devices/system/cpu/cpu0/cpuidle/state2: total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power @@ -63,6 +66,7 @@ total 0 /sys/devices/system/cpu/cpu0/cpuidle/state3: total 0 -r--r--r-- 1 root root 4096 Feb 8 10:42 desc +-rw-r--r-- 1 root root 4096 Feb 8 10:42 disable -r--r--r-- 1 root root 4096 Feb 8 10:42 latency -r--r--r-- 1 root root 4096 Feb 8 10:42 name -r--r--r-- 1 root root 4096 Feb 8 10:42 power @@ -72,6 +76,7 @@ total 0 * desc : Small description about the idle state (string) +* disable : Option to disable this idle state (bool) * latency : Latency to exit out of this idle state (in microseconds) * name : Name of the idle state (string) * power : Power consumed while in this idle state (in milliwatts) -- cgit v1.2.3 From d1ff4b1cdbabb9ab9813f3d6e1cbec42cc5d6ed8 Mon Sep 17 00:00:00 2001 From: Matthew Garrett Date: Tue, 31 Jan 2012 13:19:20 -0500 Subject: ACPI: Add support for exposing BGRT data ACPI 5.0 adds the BGRT, a table that contains a pointer to the firmware boot splash and associated metadata. This simple driver exposes it via /sys/firmware/acpi in order to allow bootsplash applications to draw their splash around the firmware image and reduce the number of jarring graphical transitions during boot. Signed-off-by: Matthew Garrett Signed-off-by: Len Brown --- Documentation/ABI/testing/sysfs-firmware-acpi | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi index 4f9ba3c2fca7..dd930c8db41f 100644 --- a/Documentation/ABI/testing/sysfs-firmware-acpi +++ b/Documentation/ABI/testing/sysfs-firmware-acpi @@ -1,3 +1,23 @@ +What: /sys/firmware/acpi/bgrt/ +Date: January 2012 +Contact: Matthew Garrett +Description: + The BGRT is an ACPI 5.0 feature that allows the OS + to obtain a copy of the firmware boot splash and + some associated metadata. This is intended to be used + by boot splash applications in order to interact with + the firmware boot splash in order to avoid jarring + transitions. + + image: The image bitmap. Currently a 32-bit BMP. + status: 1 if the image is valid, 0 if firmware invalidated it. + type: 0 indicates image is in BMP format. + version: The version of the BGRT. Currently 1. + xoffset: The number of pixels between the left of the screen + and the left edge of the image. + yoffset: The number of pixels between the top of the screen + and the top edge of the image. + What: /sys/firmware/acpi/interrupts/ Date: February 2008 Contact: Len Brown -- cgit v1.2.3