linux/kernel/power/main.c, branch v5.8

PM: sleep: Add pm_debug_messages kernel command line option

2020-04-02T13:29:56Z

Debug messages from the system suspend/hibernation infrastructure are disabled by default, and can only be enabled after the system has boot up via /sys/power/pm_debug_messages. This makes the hibernation resume hard to track as it involves system boot up across hibernation. There's no chance for software_resume() to track the resume process, for example. Add a kernel command line option to set pm_debug_messages during boot up. Signed-off-by: Chen Yu [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki

PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior

2020-01-16T20:47:03Z

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

PM: sleep: include for pm_wq

2019-10-10T09:11:56Z

Include the for the definition of pm_wq to avoid the following warning: kernel/power/main.c:890:25: warning: symbol 'pm_wq' was not declared. Should it be static? Signed-off-by: Ben Dooks Signed-off-by: Rafael J. Wysocki

PM: sleep: Replace strncmp() with str_has_prefix()

2019-08-16T12:18:53Z

Use str_has_prefix() instead of strncmp() which is less straightforward in decode_state(). Signed-off-by: Chuhong Yuan [ rjw: Subject & changelog ] Signed-off-by: Rafael J. Wysocki

PM/sleep: Expose suspend stats in sysfs

2019-08-05T10:03:18Z

Userspace can get suspend stats from the suspend stats debugfs node. Since debugfs doesn't have stable ABI, expose suspend stats in sysfs under /sys/power/suspend_stats. Signed-off-by: Kalesh Singh Reviewed-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

2019-06-05T15:37:16Z

Based on 1 normalized pattern(s): this file is released under the gplv2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 68 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Armijn Hemel Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de Signed-off-by: Greg Kroah-Hartman

PM / sleep: Measure the time of filesystems syncing

2019-04-02T08:53:19Z

Measure the filesystems sync time during system sleep more precisely. Among other things, this allows the pr_cont() to be dropped from ksys_sync_helper() and makes automatic system suspend and hibernation profiling somewhat more straightforward. Signed-off-by: Harry Pan [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki

PM / sleep: Refactor filesystems sync to reduce duplication

2019-04-02T08:53:19Z

Create a common helper to sync filesystems for system suspend and hibernation. Signed-off-by: Harry Pan Acked-by: Pavel Machek [ rjw: Changelog ] Signed-off-by: Rafael J. Wysocki

PM / sleep: convert to DEFINE_SHOW_ATTRIBUTE

2018-12-12T22:23:58Z

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code. Signed-off-by: Yangtao Li Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

PM / reboot: Eliminate race between reboot and suspend

2018-08-06T10:35:20Z

At present, "systemctl suspend" and "shutdown" can run in parrallel. A system can suspend after devices_shutdown(), and resume. Then the shutdown task goes on to power off. This causes many devices are not really shut off. Hence replacing reboot_mutex with system_transition_mutex (renamed from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as system_transition_mutex can be better to reflect the purpose of the mutex. Signed-off-by: Pingfan Liu Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki