PCI devices without drivers can be put into low power states during
suspend with the help of pci_prepare_to_sleep() and prevented from
generating wake-up events during resume with the help of
pci_enable_wake(). However, it's better not to put bridges into
low power states during suspend, because that might result in entire
bus segments being powered off.
Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx>
---
drivers/pci/pci-driver.c | 33 +++++++++++++++++++++++++++++----
1 file changed, 29 insertions(+), 4 deletions(-)
Index: linux-2.6/drivers/pci/pci-driver.c
===================================================================
--- linux-2.6.orig/drivers/pci/pci-driver.c
+++ linux-2.6/drivers/pci/pci-driver.c
@@ -421,6 +421,31 @@ static int pci_legacy_resume_early(struc
return error;
}
+/* Auxiliary functions used by the new power management framework */
+
+static bool pci_is_bridge(struct pci_dev *pci_dev)
+{
+ return !!(pci_dev->subordinate);
+}
+
+static int pci_pm_default_resume(struct pci_dev *pci_dev)
+{
+ if (!pci_is_bridge(pci_dev))
+ pci_enable_wake(pci_dev, PCI_D0, false);
+
+ return pci_default_pm_resume_late(pci_dev);
+}
+
+static void pci_pm_default_suspend(struct pci_dev *pci_dev)
+{
+ pci_default_pm_suspend_early(pci_dev);
+
+ if (!pci_is_bridge(pci_dev))
+ pci_prepare_to_sleep(pci_dev);
+}
+
+/* New power management framework */
+
static int pci_pm_prepare(struct device *dev)
{
struct device_driver *drv = dev->driver;
@@ -456,7 +481,7 @@ static int pci_pm_suspend(struct device
} else if (pci_has_legacy_pm_support(pci_dev)) {
error = pci_legacy_suspend(dev, PMSG_SUSPEND);
} else {
- pci_default_pm_suspend_early(pci_dev);
+ pci_pm_default_suspend(pci_dev);
}
pci_fixup_device(pci_fixup_suspend, pci_dev);
@@ -498,7 +523,7 @@ static int pci_pm_resume(struct device *
} else if (pci_has_legacy_pm_support(pci_dev)) {
error = pci_legacy_resume(dev);
} else {
- error = pci_default_pm_resume_late(pci_dev);
+ error = pci_pm_default_resume(pci_dev);
}
return error;
@@ -628,7 +653,7 @@ static int pci_pm_poweroff(struct device
} else if (pci_has_legacy_pm_support(pci_dev)) {
error = pci_legacy_suspend(dev, PMSG_HIBERNATE);
} else {
- pci_default_pm_suspend_early(pci_dev);
+ pci_pm_default_suspend(pci_dev);
}
pci_fixup_device(pci_fixup_suspend, pci_dev);
@@ -667,7 +692,7 @@ static int pci_pm_restore(struct device
} else if (pci_has_legacy_pm_support(pci_dev)) {
error = pci_legacy_resume(dev);
} else {
- error = pci_default_pm_resume_late(pci_dev);
+ error = pci_pm_default_resume(pci_dev);
}
return error;
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