Merge branch 'for-jens' of git://git.drbd.org/linux-drbd into for-3.6/drivers

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index bf0cee629b60..099f46cd8e87 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -748,6 +748,18 @@ static int pci_pm_suspend_noirq(struct device *dev)
 
 	pci_pm_set_unknown_state(pci_dev);
 
+	/*
+	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
+	 * PCI COMMAND register isn't 0, the BIOS assumes that the controller
+	 * hasn't been quiesced and tries to turn it off.  If the controller
+	 * is already in D3, this can hang or cause memory corruption.
+	 *
+	 * Since the value of the COMMAND register doesn't matter once the
+	 * device has been suspended, we can safely set it to 0 here.
+	 */
+	if (pci_dev->class == PCI_CLASS_SERIAL_USB_EHCI)
+		pci_write_config_word(pci_dev, PCI_COMMAND, 0);
+
 	return 0;
 }