linux/kernel/power
Thomas Gleixner c1a957d170 PM / suspend: Prevent might sleep splats
timekeeping suspend/resume calls read_persistent_clock() which takes
rtc_lock. That results in might sleep warnings because at that point
we run with interrupts disabled.

We cannot convert rtc_lock to a raw spinlock as that would trigger
other might sleep warnings.

As a workaround we disable the might sleep warnings by setting
system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and
restoring it to SYSTEM_RUNNING afer sysdev_resume(). There is no lock
contention because hibernate / suspend to RAM is single-CPU at this
point.

In s2idle's case the system_state is set to SYSTEM_SUSPEND before
timekeeping_suspend() which is invoked by the last CPU. In the resume
case it set back to SYSTEM_RUNNING after timekeeping_resume() which is
invoked by the first CPU in the resume case. The other CPUs will block
on tick_freeze_lock.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: cover s2idle in tick_freeze() / tick_unfreeze()]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-27 11:55:02 +02:00
..
autosleep.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
console.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hibernate.c PM / suspend: Prevent might sleep splats 2018-05-27 11:55:02 +02:00
Kconfig PM / OPP: Move the OPP directory out of power/ 2017-10-03 02:45:12 +02:00
main.c PM / sleep: Make lock/unlock_system_sleep() available to kernel modules 2018-01-10 01:07:46 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
power.h x86/power: Fix swsusp_arch_resume prototype 2018-02-02 23:33:50 +01:00
poweroff.c power/sysrq: fix inconstistent help message of sysrq key 2013-04-30 17:04:10 -07:00
process.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
qos.c PM / QoS: mark expected switch fall-throughs 2018-04-09 13:49:40 +02:00
snapshot.c PM: hibernate: Do not subtract NR_FILE_MAPPED in minimum_image_size() 2018-01-05 14:46:25 +01:00
suspend_test.c PM / s2idle: Rename PM_SUSPEND_FREEZE to PM_SUSPEND_TO_IDLE 2017-08-11 01:29:55 +02:00
suspend.c PM / suspend: Prevent might sleep splats 2018-05-27 11:55:02 +02:00
swap.c Merge branch 'for-4.16/block' of git://git.kernel.dk/linux-block 2018-01-29 11:51:49 -08:00
user.c fs: add ksys_sync() helper; remove in-kernel calls to sys_sync() 2018-04-02 20:16:05 +02:00
wakelock.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00