[PATCH v4 4/5] PM / sleep: Asynchronous threads for suspend_noirq

From: Chuansheng Liu
Date: Mon Feb 17 2014 - 21:39:34 EST


In analogy with commits 5af84b82701a and 97df8c12995, using
asynchronous threads can improve the overall suspend_noirq
time significantly.

This patch is for suspend_noirq phase.

Signed-off-by: Chuansheng Liu <chuansheng.liu@xxxxxxxxx>
---
drivers/base/power/main.c | 68 +++++++++++++++++++++++++++++++++++++++--------
1 file changed, 57 insertions(+), 11 deletions(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 6d41165..9335b32 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -990,14 +990,24 @@ static pm_message_t resume_event(pm_message_t sleep_state)
* The driver of @dev will not receive interrupts while this function is being
* executed.
*/
-static int device_suspend_noirq(struct device *dev, pm_message_t state)
+static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool async)
{
pm_callback_t callback = NULL;
char *info = NULL;
- int error;
+ int error = 0;
+
+ if (async_error)
+ goto Complete;
+
+ if (pm_wakeup_pending()) {
+ async_error = -EBUSY;
+ goto Complete;
+ }

if (dev->power.syscore)
- return 0;
+ goto Complete;
+
+ dpm_wait_for_children(dev, async);

if (dev->pm_domain) {
info = "noirq power domain ";
@@ -1021,10 +1031,40 @@ static int device_suspend_noirq(struct device *dev, pm_message_t state)
error = dpm_run_callback(callback, dev, state, info);
if (!error)
dev->power.is_noirq_suspended = true;
+ else
+ async_error = error;

+Complete:
+ complete_all(&dev->power.completion);
return error;
}

+static void async_suspend_noirq(void *data, async_cookie_t cookie)
+{
+ struct device *dev = (struct device *)data;
+ int error;
+
+ error = __device_suspend_noirq(dev, pm_transition, true);
+ if (error) {
+ dpm_save_failed_dev(dev_name(dev));
+ pm_dev_err(dev, pm_transition, " async", error);
+ }
+
+ put_device(dev);
+}
+
+static int device_suspend_noirq(struct device *dev)
+{
+ reinit_completion(&dev->power.completion);
+
+ if (pm_async_enabled && dev->power.async_suspend) {
+ get_device(dev);
+ async_schedule(async_suspend_noirq, dev);
+ return 0;
+ }
+ return __device_suspend_noirq(dev, pm_transition, false);
+}
+
/**
* dpm_suspend_noirq - Execute "noirq suspend" callbacks for all devices.
* @state: PM transition of the system being carried out.
@@ -1040,19 +1080,20 @@ static int dpm_suspend_noirq(pm_message_t state)
cpuidle_pause();
suspend_device_irqs();
mutex_lock(&dpm_list_mtx);
+ pm_transition = state;
+ async_error = 0;
+
while (!list_empty(&dpm_late_early_list)) {
struct device *dev = to_device(dpm_late_early_list.prev);

get_device(dev);
mutex_unlock(&dpm_list_mtx);

- error = device_suspend_noirq(dev, state);
+ error = device_suspend_noirq(dev);

mutex_lock(&dpm_list_mtx);
if (error) {
pm_dev_err(dev, state, " noirq", error);
- suspend_stats.failed_suspend_noirq++;
- dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
dpm_save_failed_dev(dev_name(dev));
put_device(dev);
break;
@@ -1061,16 +1102,21 @@ static int dpm_suspend_noirq(pm_message_t state)
list_move(&dev->power.entry, &dpm_noirq_list);
put_device(dev);

- if (pm_wakeup_pending()) {
- error = -EBUSY;
+ if (async_error)
break;
- }
}
mutex_unlock(&dpm_list_mtx);
- if (error)
+ async_synchronize_full();
+ if (!error)
+ error = async_error;
+
+ if (error) {
+ suspend_stats.failed_suspend_noirq++;
+ dpm_save_failed_step(SUSPEND_SUSPEND_NOIRQ);
dpm_resume_noirq(resume_event(state));
- else
+ } else {
dpm_show_time(starttime, state, "noirq");
+ }
return error;
}

--
1.9.rc0

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