From a6cbaadea0af9b4aa6eee2882f2aa761ab91a4f8 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 8 Aug 2013 14:10:02 -0600 Subject: [PATCH] PCI: Wake-up devices before saving config space for reset Devices come out of reset in D0. Restoring a device to a different post-reset state takes more smarts than our simple config space restore, which can leave devices in an inconsistent state. For example, if a device is reset in D3, but the restore doesn't successfully return the device to D3, then the actual state of the device and dev->current_state are contradictory. Put everything in D0 going into the reset, then we don't need to do anything special on the way out. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 12fccc24925c..deb7fa9cc638 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3332,6 +3332,13 @@ static void pci_dev_unlock(struct pci_dev *dev) static void pci_dev_save_and_disable(struct pci_dev *dev) { + /* + * Wake-up device prior to save. PM registers default to D0 after + * reset and a simple register restore doesn't reliably return + * to a non-D0 state anyway. + */ + pci_set_power_state(dev, PCI_D0); + pci_save_state(dev); /* * Disable the device by clearing the Command register, except for