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authorRafael J. Wysocki <rjw@sisk.pl>2011-02-12 01:42:41 +0100
committerRafael J. Wysocki <rjw@sisk.pl>2011-03-15 00:43:16 +0100
commite8665002477f0278f84f898145b1f141ba26ee26 (patch)
treef22348cc3c0cf341216d422e01d2ac033973a0a5
parent88a6f33e4d7143f94f8e787fa4065ac873507984 (diff)
PM: Allow pm_runtime_suspend() to succeed during system suspend
The dpm_prepare() function increments the runtime PM reference counters of all devices to prevent pm_runtime_suspend() from executing subsystem-level callbacks. However, this was supposed to guard against a specific race condition that cannot happen, because the power management workqueue is freezable, so pm_runtime_suspend() can only be called synchronously during system suspend and we can rely on subsystems and device drivers to avoid doing that unnecessarily. Make dpm_prepare() drop the runtime PM reference to each device after making sure that runtime resume is not pending for it. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Kevin Hilman <khilman@ti.com>
-rw-r--r--drivers/base/power/main.c10
1 files changed, 3 insertions, 7 deletions
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 83404973f97a..f7a755923751 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -669,7 +669,6 @@ static void dpm_complete(pm_message_t state)
mutex_unlock(&dpm_list_mtx);
device_complete(dev, state);
- pm_runtime_put_sync(dev);
mutex_lock(&dpm_list_mtx);
put_device(dev);
@@ -1005,12 +1004,9 @@ static int dpm_prepare(pm_message_t state)
if (pm_runtime_barrier(dev) && device_may_wakeup(dev))
pm_wakeup_event(dev, 0);
- if (pm_wakeup_pending()) {
- pm_runtime_put_sync(dev);
- error = -EBUSY;
- } else {
- error = device_prepare(dev, state);
- }
+ pm_runtime_put_sync(dev);
+ error = pm_wakeup_pending() ?
+ -EBUSY : device_prepare(dev, state);
mutex_lock(&dpm_list_mtx);
if (error) {