From 75a80267410e38ab76c4ceb39753f96d72113781 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 13 Dec 2019 09:56:13 +0100 Subject: cpuidle: Allow idle states to be disabled by default In certain situations it may be useful to prevent some idle states from being used by default while allowing user space to enable them later on. For this purpose, introduce a new state flag, CPUIDLE_FLAG_OFF, to mark idle states that should be disabled by default, make the core set CPUIDLE_STATE_DISABLED_BY_USER for those states at the initialization time and add a new state attribute in sysfs, "default_status", to inform user space of the initial status of the given idle state ("disabled" if CPUIDLE_FLAG_OFF is set for it, "enabled" otherwise). Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-devices-system-cpu | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/ABI/testing') diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index fc20cde63d1e..2e0e3b45d02a 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -196,6 +196,12 @@ Description: does not reflect it. Likewise, if one enables a deep state but a lighter state still is disabled, then this has no effect. +What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status +Date: December 2019 +KernelVersion: v5.6 +Contact: Linux power management list +Description: + (RO) The default status of this state, "enabled" or "disabled". What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency Date: March 2014 -- cgit v1.2.3 From 2fee1a7cc6b1ce6634bb0f025be2c94a58dfa34d Mon Sep 17 00:00:00 2001 From: Chanwoo Choi Date: Tue, 5 Nov 2019 18:18:03 +0900 Subject: PM / devfreq: Add new name attribute for sysfs The commit 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs") changed the node name to devfreq(x). After this commit, it is not possible to get the device name through /sys/class/devfreq/devfreq(X)/*. Add new name attribute in order to get device name. Cc: stable@vger.kernel.org Fixes: 4585fbcb5331 ("PM / devfreq: Modify the device name as devfreq(X) for sysfs") Signed-off-by: Chanwoo Choi --- Documentation/ABI/testing/sysfs-class-devfreq | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'Documentation/ABI/testing') diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 01196e19afca..75897e2fde43 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -7,6 +7,13 @@ Description: The name of devfreq object denoted as ... is same as the name of device using devfreq. +What: /sys/class/devfreq/.../name +Date: November 2019 +Contact: Chanwoo Choi +Description: + The /sys/class/devfreq/.../name shows the name of device + of the corresponding devfreq object. + What: /sys/class/devfreq/.../governor Date: September 2011 Contact: MyungJoo Ham -- cgit v1.2.3 From 14a34396819960865ff737c665c6e46b64d0e04a Mon Sep 17 00:00:00 2001 From: Kamil Konieczny Date: Thu, 5 Dec 2019 15:55:26 +0100 Subject: PM / devfreq: Add clearing transitions stats Add clearing transition table and time in states devfreq statistics by writing 0 (zero) to trans_stat file in devfreq sysfs. An example use is like following: echo 0 > /sys/class/devfreq/devfreqX/trans_stat Signed-off-by: Kamil Konieczny [cw00.choi: Edit return value if entering the wrong value for reset and use arrary3_size() to get the size of 3-dimensional array] Signed-off-by: Chanwoo Choi --- Documentation/ABI/testing/sysfs-class-devfreq | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'Documentation/ABI/testing') diff --git a/Documentation/ABI/testing/sysfs-class-devfreq b/Documentation/ABI/testing/sysfs-class-devfreq index 75897e2fde43..9758eb85ade3 100644 --- a/Documentation/ABI/testing/sysfs-class-devfreq +++ b/Documentation/ABI/testing/sysfs-class-devfreq @@ -55,12 +55,15 @@ What: /sys/class/devfreq/.../trans_stat Date: October 2012 Contact: MyungJoo Ham Description: - This ABI shows the statistics of devfreq behavior on a - specific device. It shows the time spent in each state and - the number of transitions between states. + This ABI shows or clears the statistics of devfreq behavior + on a specific device. It shows the time spent in each state + and the number of transitions between states. In order to activate this ABI, the devfreq target device driver should provide the list of available frequencies - with its profile. + with its profile. If need to reset the statistics of devfreq + behavior on a specific device, enter 0(zero) to 'trans_stat' + as following: + echo 0 > /sys/class/devfreq/.../trans_stat What: /sys/class/devfreq/.../userspace/set_freq Date: September 2011 -- cgit v1.2.3 From c052bf82c6b00ca27aab0859addc4b3159dfd3a4 Mon Sep 17 00:00:00 2001 From: Jonas Meurer Date: Thu, 16 Jan 2020 12:53:54 +0100 Subject: PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not filesystems are synced by the kernel before system suspend. Congruously, the behaviour of build-time switch CONFIG_SUSPEND_SKIP_SYNC is slightly changed: It now defines the run-tim default for the new sysfs attribute `/sys/power/sync_on_suspend`. The run-time attribute is added because the existing corresponding build-time Kconfig flag for (`CONFIG_SUSPEND_SKIP_SYNC`) is not flexible enough. E.g. Linux distributions that provide pre-compiled kernels usually want to stick with the default (sync filesystems before suspend) but under special conditions this needs to be changed. One example for such a special condition is user-space handling of suspending block devices (e.g. using `cryptsetup luksSuspend` or `dmsetup suspend`) before system suspend. The Kernel trying to sync filesystems after the underlying block device already got suspended obviously leads to dead-locks. Be aware that you have to take care of the filesystem sync yourself before suspending the system in those scenarios. Signed-off-by: Jonas Meurer Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-power | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'Documentation/ABI/testing') diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 6f87b9dd384b..5e6ead29124c 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -407,3 +407,16 @@ Contact: Kalesh Singh Description: The /sys/power/suspend_stats/last_failed_step file contains the last failed step in the suspend/resume path. + +What: /sys/power/sync_on_suspend +Date: October 2019 +Contact: Jonas Meurer +Description: + This file controls whether or not the kernel will sync() + filesystems during system suspend (after freezing user space + and before suspending devices). + + Writing a "1" to this file enables the sync() and writing a "0" + disables it. Reads from the file return the current value. + The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config + flag is unset, or "0" otherwise. -- cgit v1.2.3