usb: Prevent dead ports when xhci is not enabled

commit 58b2939b4d5a030eaec469d29812ab8477ee7e76 upstream.

When the xHCI driver is not available, actively switch the ports to EHCI
mode since some BIOSes leave them in xHCI mode where they would
otherwise appear dead.  This was discovered on a  Dell Optiplex 7010,
but it's possible other systems could be affected.

This should be backported to kernels as old as 3.0, that contain the
commit 69e848c2090aebba5698a1620604c7dccb448684 "Intel xhci: Support
EHCI/xHCI port switching."

Signed-off-by: David Moore <david.moore@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index eb5563ac58bc8a504cde1ed3552d625d0c2ed0f5..78933512c18bf30bebe51c61603508fcf3c5745f 100644 (file)
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -780,6 +780,7 @@ void usb_enable_xhci_ports(struct pci_dev *xhci_pdev)
                                "defaulting to EHCI.\n");
                dev_warn(&xhci_pdev->dev,
                                "USB 3.0 devices will work at USB 2.0 speeds.\n");
+               usb_disable_xhci_ports(xhci_pdev);
                return;
        }