diff options
Diffstat (limited to 'drivers/pci/pci-driver.c')
| -rw-r--r-- | drivers/pci/pci-driver.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index bf0cee629b6..099f46cd8e8 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; } |