From 88d26136a256576e444db312179e17af6dd0ea87 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 19 Sep 2012 21:59:02 +0200 Subject: PM: Prevent runtime suspend during system resume This patch (as1591) moves the pm_runtime_get_noresume() and pm_runtime_put_sync() calls from __device_suspend() and device_resume() to device_prepare() and device_complete() in the PM core. The reason for doing this is to make sure that parent devices remain at full power (i.e., don't go into runtime suspend) while their children are being resumed from a system sleep. The PCI core already contained equivalent code to serve the same purpose. The patch removes the duplicated code, since it is no longer needed. One of the comments from the PCI core gets moved into the PM core, and a second comment is added to explain whe the _get_noresume and _put_sync calls are present. Signed-off-by: Alan Stern Signed-off-by: Rafael J. Wysocki --- drivers/base/power/main.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 2700f2e4066f..077b9756fd8f 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -565,7 +565,6 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) pm_callback_t callback = NULL; char *info = NULL; int error = 0; - bool put = false; TRACE_DEVICE(dev); TRACE_RESUME(0); @@ -583,7 +582,6 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) goto Unlock; pm_runtime_enable(dev); - put = true; if (dev->pm_domain) { info = "power domain "; @@ -636,9 +634,6 @@ static int device_resume(struct device *dev, pm_message_t state, bool async) TRACE_RESUME(error); - if (put) - pm_runtime_put_sync(dev); - return error; } @@ -749,6 +744,8 @@ static void device_complete(struct device *dev, pm_message_t state) } device_unlock(dev); + + pm_runtime_put_sync(dev); } /** @@ -1043,12 +1040,16 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) if (async_error) goto Complete; - pm_runtime_get_noresume(dev); + /* + * If a device configured to wake up the system from sleep states + * has been suspended at run time and there's a resume request pending + * for it, this is equivalent to the device signaling wakeup, so the + * system suspend operation should be aborted. + */ if (pm_runtime_barrier(dev) && device_may_wakeup(dev)) pm_wakeup_event(dev, 0); if (pm_wakeup_pending()) { - pm_runtime_put_sync(dev); async_error = -EBUSY; goto Complete; } @@ -1111,12 +1112,10 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) Complete: complete_all(&dev->power.completion); - if (error) { - pm_runtime_put_sync(dev); + if (error) async_error = error; - } else if (dev->power.is_suspended) { + else if (dev->power.is_suspended) __pm_runtime_disable(dev, false); - } return error; } @@ -1209,6 +1208,14 @@ static int device_prepare(struct device *dev, pm_message_t state) char *info = NULL; int error = 0; + /* + * If a device's parent goes into runtime suspend at the wrong time, + * it won't be possible to resume the device. To prevent this we + * block runtime suspend here, during the prepare phase, and allow + * it again during the complete phase. + */ + pm_runtime_get_noresume(dev); + device_lock(dev); dev->power.wakeup_path = device_may_wakeup(dev); -- cgit v1.2.3