diff options
authorRafael J. Wysocki <>2009-05-17 20:17:06 +0200
committerJesse Barnes <>2009-05-19 15:26:07 -0700
commitb3bad72e494fb2ff0c81be4ca2ddb94adf6a47c2 (patch)
parent279e677faa775ad16e75c32e1bf4a37f8158bc61 (diff)
PCI PM: Fix initialization and kexec breakage for some devices
Recent PCI PM changes introduced a bug that causes some devices to be mishandled after kexec and during early initialization. The failure scenario in the kexec case is the following: * Assume a PCI device is not power-manageable by the platform and has PCI_PM_CTRL_NO_SOFT_RESET set in PMCSR. * The device is put into D3 before kexec (using the native PCI PM). * After kexec, pci_setup_device() sets the device's power state to PCI_UNKNOWN. * pci_set_power_state(dev, PCI_D0) is called by the device's driver. * __pci_start_power_transition(dev, PCI_D0) is called and since the device is not power-manageable by the platform, it causes pci_update_current_state(dev, PCI_D0) to be called. As a result the device's current_state field is updated to PCI_D3, in accordance with the contents of its PCI PM registers. * pci_raw_set_power_state() is called and it changes the device power state to D0. *However*, it should also call pci_restore_bars() to reinitialize the device, but it doesn't, because the device's current_state field has been modified earlier. To prevent this from happening, modify pci_platform_power_transition() so that it doesn't use pci_update_current_state() to update the current_state field for devices that aren't power-manageable by the platform. Instead, this field should be updated directly for devices that don't support the native PCI PM. Signed-off-by: Rafael J. Wysocki <> Signed-off-by: Jesse Barnes <>
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 34bf0fdf5047..1a91bf9687af 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -557,7 +557,8 @@ static int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state)
} else {
error = -ENODEV;
/* Fall back to PCI_D0 if native PM is not supported */
- pci_update_current_state(dev, PCI_D0);
+ if (!dev->pm_cap)
+ dev->current_state = PCI_D0;
return error;