Messages in this thread Patch in this message | | | Subject | [PATCH 8/8] pci: Wake-up devices before save for reset | From | Alex Williamson <> | Date | Tue, 07 May 2013 17:25:11 -0600 |
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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 <alex.williamson@redhat.com> --- drivers/pci/pci.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 8647998..98372ec 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3312,6 +3312,13 @@ static void pci_dev_unlock(struct pci_dev *dev) static void pci_dev_save(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); /* * both INTx and MSI are disabled after the Interrupt Disable bit
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