Vincent Guittot 15efb47dc5 PM-runtime: Fix deadlock with ktime_get() ... A deadlock has been seen when swicthing clocksources which use PM-runtime. The call path is: change_clocksource ... write_seqcount_begin ... timekeeping_update ... sh_cmt_clocksource_enable ... rpm_resume pm_runtime_mark_last_busy ktime_get do read_seqcount_begin while read_seqcount_retry .... write_seqcount_end Although we should be safe because we haven't yet changed the clocksource at that time, we can't do that because of seqcount protection. Use ktime_get_mono_fast_ns() instead which is lock safe for such cases. With ktime_get_mono_fast_ns, the timestamp is not guaranteed to be monotonic across an update and as a result can goes backward. According to update_fast_timekeeper() description: "In the worst case, this can result is a slightly wrong timestamp (a few nanoseconds)". For PM-runtime autosuspend, this means only that the suspend decision may be slightly suboptimal. Fixes: 8234f6734c ("PM-runtime: Switch autosuspend over to using hrtimers") Reported-by: Biju Das <biju.das@bp.renesas.com> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>		2019-01-30 22:49:06 +01:00
..
clock_ops.c
common.c
domain_governor.c
domain.c	Merge branches 'pm-core', 'pm-qos', 'pm-domains' and 'pm-sleep'	2018-12-21 10:06:44 +01:00
generic_ops.c
main.c	PM: sleep: call devfreq suspend/resume	2019-01-02 23:07:41 +01:00
Makefile
power.h
qos.c
runtime.c	PM-runtime: Fix deadlock with ktime_get()	2019-01-30 22:49:06 +01:00
sysfs.c
trace.c	PM: Switch to use %ptR	2018-12-10 22:40:18 +01:00
wakeirq.c
wakeup.c