[PATCH] improve timekeeping resume robustness (3e143475) · Commits · 戴 / test

kernel/timer.c

+18 −1

Original line number	Diff line number	Diff line
		@@ -969,6 +969,7 @@ void __init timekeeping_init(void)
		}


		static int timekeeping_suspended;
		/*
		* timekeeping_resume - Resumes the generic timekeeping subsystem.
		* @dev: unused
		@@ -984,6 +985,18 @@ static int timekeeping_resume(struct sys_device *dev)
		write_seqlock_irqsave(&xtime_lock, flags);
		/* restart the last cycle value */
		clock->cycle_last = clocksource_read(clock);
		clock->error = 0;
		timekeeping_suspended = 0;
		write_sequnlock_irqrestore(&xtime_lock, flags);
		return 0;
		}

		static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
		{
		unsigned long flags;

		write_seqlock_irqsave(&xtime_lock, flags);
		timekeeping_suspended = 1;
		write_sequnlock_irqrestore(&xtime_lock, flags);
		return 0;
		}
		@@ -991,6 +1004,7 @@ static int timekeeping_resume(struct sys_device *dev)
		/* sysfs resume/suspend bits for timekeeping */
		static struct sysdev_class timekeeping_sysclass = {
		.resume = timekeeping_resume,
		.suspend = timekeeping_suspend,
		set_kset_name("timekeeping"),
		};

		@@ -1101,13 +1115,16 @@ static void update_wall_time(void)
		{
		cycle_t offset;

		clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift;
		/* Make sure we're fully resumed: */
		if (unlikely(timekeeping_suspended))
		return;

		#ifdef CONFIG_GENERIC_TIME
		offset = (clocksource_read(clock) - clock->cycle_last) & clock->mask;
		#else
		offset = clock->cycle_interval;
		#endif
		clock->xtime_nsec += (s64)xtime.tv_nsec << clock->shift;

		/* normally this loop will run just once, however in the
		* case of lost or late ticks, it will accumulate correctly.

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