Commit 76569faa authored by Liu, Chuansheng's avatar Liu, Chuansheng Committed by Rafael J. Wysocki
Browse files

PM / sleep: Asynchronous threads for resume_noirq 



In analogy with commits 5af84b82 and 97df8c12, using
asynchronous threads can improve the overall resume_noirq time
significantly.

One typical case is:
In resume_noirq phase and for the PCI devices, the function
pci_pm_resume_noirq() will be called, and there is one d3_delay
(10ms) at least.

With the way of asynchronous threads, we just need wait d3_delay
time once in parallel for each calling, which saves much time to
resume quickly.

Signed-off-by: default avatarChuansheng Liu <chuansheng.liu@intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 3d2699bc

drivers/base/power/main.c

+50 −16
Original line number Diff line number Diff line
@@ -469,7 +469,7 @@ static void dpm_watchdog_clear(struct dpm_watchdog *wd) 
 * The driver of @dev will not receive interrupts while this function is being

 * executed.

 */

static int device_resume_noirq(struct device *dev, pm_message_t state)

static int device_resume_noirq(struct device *dev, pm_message_t state, bool async)

{

	pm_callback_t callback = NULL;

	char *info = NULL;
@@ -484,6 +484,8 @@ static int device_resume_noirq(struct device *dev, pm_message_t state) 
	if (!dev->power.is_noirq_suspended)

		goto Out;



	dpm_wait(dev->parent, async);



	if (dev->pm_domain) {

		info = "noirq power domain ";

		callback = pm_noirq_op(&dev->pm_domain->ops, state);
@@ -507,10 +509,29 @@ static int device_resume_noirq(struct device *dev, pm_message_t state) 
	dev->power.is_noirq_suspended = false;



 Out:

	complete_all(&dev->power.completion);

	TRACE_RESUME(error);

	return error;

}



static bool is_async(struct device *dev)

{

	return dev->power.async_suspend && pm_async_enabled

		&& !pm_trace_is_enabled();

}



static void async_resume_noirq(void *data, async_cookie_t cookie)

{

	struct device *dev = (struct device *)data;

	int error;



	error = device_resume_noirq(dev, pm_transition, true);

	if (error)

		pm_dev_err(dev, pm_transition, " async", error);



	put_device(dev);

}



/**

 * dpm_resume_noirq - Execute "noirq resume" callbacks for all devices.

 * @state: PM transition of the system being carried out.
@@ -520,29 +541,48 @@ static int device_resume_noirq(struct device *dev, pm_message_t state) 
 */

static void dpm_resume_noirq(pm_message_t state)

{

	struct device *dev;

	ktime_t starttime = ktime_get();



	mutex_lock(&dpm_list_mtx);

	while (!list_empty(&dpm_noirq_list)) {

		struct device *dev = to_device(dpm_noirq_list.next);

		int error;

	pm_transition = state;



	/*

	 * Advanced the async threads upfront,

	 * in case the starting of async threads is

	 * delayed by non-async resuming devices.

	 */

	list_for_each_entry(dev, &dpm_noirq_list, power.entry) {

		reinit_completion(&dev->power.completion);

		if (is_async(dev)) {

			get_device(dev);

			async_schedule(async_resume_noirq, dev);

		}

	}



	while (!list_empty(&dpm_noirq_list)) {

		dev = to_device(dpm_noirq_list.next);

		get_device(dev);

		list_move_tail(&dev->power.entry, &dpm_late_early_list);

		mutex_unlock(&dpm_list_mtx);



		error = device_resume_noirq(dev, state);

		if (!is_async(dev)) {

			int error;



			error = device_resume_noirq(dev, state, false);

			if (error) {

				suspend_stats.failed_resume_noirq++;

				dpm_save_failed_step(SUSPEND_RESUME_NOIRQ);

				dpm_save_failed_dev(dev_name(dev));

				pm_dev_err(dev, state, " noirq", error);

			}

		}



		mutex_lock(&dpm_list_mtx);

		put_device(dev);

	}

	mutex_unlock(&dpm_list_mtx);

	async_synchronize_full();

	dpm_show_time(starttime, state, "noirq");

	resume_device_irqs();

	cpuidle_resume();
@@ -742,12 +782,6 @@ static void async_resume(void *data, async_cookie_t cookie) 
	put_device(dev);

}



static bool is_async(struct device *dev)

{

	return dev->power.async_suspend && pm_async_enabled

		&& !pm_trace_is_enabled();

}



/**

 * dpm_resume - Execute "resume" callbacks for non-sysdev devices.

 * @state: PM transition of the system being carried out.

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