PM / Sleep: Print last wakeup source on failed wakeup_count write (bb177fed) · Commits · 戴 / test

Commit introduced a useful little log message to tell users/debuggers which wakeup source aborted a suspend. However, this message is only printed if the abort happens during the in-kernel suspend path (after writing /sys/power/state). The full specification of the /sys/power/wakeup_count facility allows user-space power managers to double-check if wakeups have already happened before it actually tries to suspend (e.g. while it was running user-space pre-suspend hooks), by writing the last known wakeup_count value to /sys/power/wakeup_count. This patch changes the sysfs handler for that node to also print said log message if that write fails, so that we can figure out the offending wakeup source for both kinds of suspend aborts. Signed-off-by:

Julius Werner <jwerner@chromium.org> Signed-off-by:

Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/wakeup.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -659,7 +659,7 @@ void pm_wakeup_event(struct device *dev, unsigned int msec)
		}
		EXPORT_SYMBOL_GPL(pm_wakeup_event);

		static void print_active_wakeup_sources(void)
		void pm_print_active_wakeup_sources(void)
		{
		struct wakeup_source *ws;
		int active = 0;
		@@ -683,6 +683,7 @@ static void print_active_wakeup_sources(void)
		last_activity_ws->name);
		rcu_read_unlock();
		}
		EXPORT_SYMBOL_GPL(pm_print_active_wakeup_sources);

		/**
		* pm_wakeup_pending - Check if power transition in progress should be aborted.
		@@ -709,7 +710,7 @@ bool pm_wakeup_pending(void)

		if (ret) {
		pr_info("PM: Wakeup pending, aborting suspend\n");
		print_active_wakeup_sources();
		pm_print_active_wakeup_sources();
		}

		return ret;

include/linux/suspend.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -363,6 +363,7 @@ extern bool pm_wakeup_pending(void);
		extern bool pm_get_wakeup_count(unsigned int *count, bool block);
		extern bool pm_save_wakeup_count(unsigned int count);
		extern void pm_wakep_autosleep_enabled(bool set);
		extern void pm_print_active_wakeup_sources(void);

		static inline void lock_system_sleep(void)
		{

kernel/power/main.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -424,6 +424,8 @@ static ssize_t wakeup_count_store(struct kobject *kobj,
		if (sscanf(buf, "%u", &val) == 1) {
		if (pm_save_wakeup_count(val))
		error = n;
		else
		pm_print_active_wakeup_sources();
		}

		out:

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