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: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 5cc401bfab3ad7762f66fea0c78bad9c8bf435b4..c7cfbce3371c0bfabf4d3f724ba96dbacc9c7cff 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;
        }