[v4,7/9] pci: Wake-up devices before save for reset

Message ID 20130805193746.9260.8439.stgit@bling.home
State Not Applicable
Headers show

Commit Message

Alex Williamson Aug. 5, 2013, 7:37 p.m.
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(+)

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diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1dba7dd..b204206 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);
 	 * Disable the device by clearing the Command register, except for