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| author | Rafael J. Wysocki <rjw@sisk.pl> | 2011-02-12 01:42:41 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-03-15 00:43:16 +0100 |
| commit | e8665002477f0278f84f898145b1f141ba26ee26 (patch) | |
| tree | f22348cc3c0cf341216d422e01d2ac033973a0a5 /drivers/base | |
| parent | 88a6f33e4d7143f94f8e787fa4065ac873507984 (diff) | |
| download | lwn-e8665002477f0278f84f898145b1f141ba26ee26.tar.gz lwn-e8665002477f0278f84f898145b1f141ba26ee26.zip | |
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>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/power/main.c | 10 |
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) { |