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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-02-26 01:00:30 +0100
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-03-04 00:18:16 +0100
commit7cd0602d7836c0056fe9bdab014d5ac5ec5cb291 (patch)
tree26439c4d133faad178777b94c5fde732e7619eee /drivers/pci
parent92858c476ec4e99cf0425f05dee109b6a55eb6f8 (diff)
downloadlinux-7cd0602d7836c0056fe9bdab014d5ac5ec5cb291.tar.bz2
PCI / PM: Resume runtime-suspended devices later during system suspend
Runtime-suspended devices are resumed during system suspend by pci_pm_prepare() for two reasons: First, because they may need to be reprogrammed in order to change their wakeup settings and, second, because they may need to be operatonal for their children to be successfully suspended. That is a problem, though, if there are many runtime-suspended devices that need to be resumed this way during system suspend, because the .prepare() PM callbacks of devices are executed sequentially and the times taken by them accumulate, which may increase the total system suspend time quite a bit. For this reason, move the resume of runtime-suspended devices up to the next phase of device suspend (during system suspend), except for the ones that have power.ignore_children set. The exception is made, because the devices with power.ignore_children set may still be necessary for their children to be successfully suspended (during system suspend) and they won't be resumed automatically as a result of the runtime resume of their children. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/pci-driver.c33
1 files changed, 25 insertions, 8 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 25f0bc659164..d911e0c1f359 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -616,15 +616,11 @@ static int pci_pm_prepare(struct device *dev)
int error = 0;
/*
- * PCI devices suspended at run time need to be resumed at this
- * point, because in general it is necessary to reconfigure them for
- * system suspend. Namely, if the device is supposed to wake up the
- * system from the sleep state, we may need to reconfigure it for this
- * purpose. In turn, if the device is not supposed to wake up the
- * system from the sleep state, we'll have to prevent it from signaling
- * wake-up.
+ * Devices having power.ignore_children set may still be necessary for
+ * suspending their children in the next phase of device suspend.
*/
- pm_runtime_resume(dev);
+ if (dev->power.ignore_children)
+ pm_runtime_resume(dev);
if (drv && drv->pm && drv->pm->prepare)
error = drv->pm->prepare(dev);
@@ -654,6 +650,16 @@ static int pci_pm_suspend(struct device *dev)
goto Fixup;
}
+ /*
+ * PCI devices suspended at run time need to be resumed at this point,
+ * because in general it is necessary to reconfigure them for system
+ * suspend. Namely, if the device is supposed to wake up the system
+ * from the sleep state, we may need to reconfigure it for this purpose.
+ * In turn, if the device is not supposed to wake up the system from the
+ * sleep state, we'll have to prevent it from signaling wake-up.
+ */
+ pm_runtime_resume(dev);
+
pci_dev->state_saved = false;
if (pm->suspend) {
pci_power_t prev = pci_dev->current_state;
@@ -808,6 +814,14 @@ static int pci_pm_freeze(struct device *dev)
return 0;
}
+ /*
+ * This used to be done in pci_pm_prepare() for all devices and some
+ * drivers may depend on it, so do it here. Ideally, runtime-suspended
+ * devices should not be touched during freeze/thaw transitions,
+ * however.
+ */
+ pm_runtime_resume(dev);
+
pci_dev->state_saved = false;
if (pm->freeze) {
int error;
@@ -915,6 +929,9 @@ static int pci_pm_poweroff(struct device *dev)
goto Fixup;
}
+ /* The reason to do that is the same as in pci_pm_suspend(). */
+ pm_runtime_resume(dev);
+
pci_dev->state_saved = false;
if (pm->poweroff) {
int error;