xhci: Do not issue device reset when device is not setup

BugLink: http://bugs.launchpad.net/bugs/802541

xHCI controllers respond to a Reset Device command when the Slot is in the
Enabled/Disabled state by returning an error.  This is fine on other host
controllers, but the Etron xHCI host controller returns a vendor-specific
error code that the xHCI driver doesn't understand.  The xHCI driver then
gives up on device enumeration.

Instead of issuing a command that will fail, just return.  This fixes the
issue with the xhci driver not working on ASRock P67 Pro/Extreme boards.

This should be backported to stable kernels as far back as 2.6.34.

Signed-off-by: Maarten Lankhorst <m.b.lankhorst@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@kernel.org
(cherry picked from commit 001fd3826f4c736ce292315782d015f768399080)
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index df05580..b06d412 100644 (file)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2228,6 +2228,7 @@ int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
        struct xhci_command *reset_device_cmd;
        int timeleft;
        int last_freed_endpoint;
+       struct xhci_slot_ctx *slot_ctx;
 
        ret = xhci_check_args(hcd, udev, NULL, 0, false, __func__);
        if (ret <= 0)
@@ -2260,6 +2261,12 @@ int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
                        return -EINVAL;
        }
 
+       /* If device is not setup, there is no point in resetting it */
+       slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
+       if (GET_SLOT_STATE(le32_to_cpu(slot_ctx->dev_state)) ==
+                                               SLOT_STATE_DISABLED)
+               return 0;
+
        xhci_dbg(xhci, "Resetting device with slot ID %u\n", slot_id);
        /* Allocate the command structure that holds the struct completion.
         * Assume we're in process context, since the normal device reset