tick/common: Touch watchdog in tick_unfreeze() on all CPUs

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>

diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index a02e0f6b287cec0b8798bdc9761f5e7e0041e08f..0a3cc37e4b8387a067ba8e2ed49fbf31678c4853 100644 (file)
--- 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();
        }