From: Chunyan Zhang zhang.lyra@gmail.com
stable inclusion from linux-4.19.158 commit 880d94c7811ebe89ab7edc7e8839ccdf0eedcd91
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commit 5167c506d62dd9ffab73eba23c79b0a8845c9fe1 upstream.
Suspend to IDLE invokes tick_unfreeze() on resume. tick_unfreeze() on the first resuming CPU resumes timekeeping, which also has the side effect of resetting the softlockup watchdog on this CPU.
But on the secondary CPUs the watchdog is not reset in the resume / unfreeze() path, which can result in false softlockup warnings on those CPUs depending on the time spent in suspend.
Prevent this by clearing the softlock watchdog in the unfreeze path also on the secondary resuming CPUs.
[ tglx: Massaged changelog ]
Signed-off-by: Chunyan Zhang chunyan.zhang@unisoc.com Signed-off-by: Thomas Gleixner tglx@linutronix.de Link: https://lore.kernel.org/r/20200110083902.27276-1-chunyan.zhang@unisoc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- kernel/time/tick-common.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index a02e0f6b287c..0a3cc37e4b83 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -15,6 +15,7 @@ #include <linux/err.h> #include <linux/hrtimer.h> #include <linux/interrupt.h> +#include <linux/nmi.h> #include <linux/percpu.h> #include <linux/profile.h> #include <linux/sched.h> @@ -520,6 +521,7 @@ void tick_unfreeze(void) trace_suspend_resume(TPS("timekeeping_freeze"), smp_processor_id(), false); } else { + touch_softlockup_watchdog(); tick_resume_local(); }