xhci: Silence "xHCI xhci_drop_endpoint called with disabled ep ..." messages

When re-applying the configuration after a successful usb device reset,
xhci_discover_or_reset_device has already dropped the endpoints, and free-ed
the rings.

The endpoints already being dropped is expected, and should not lead to
warnings. Use the fact that the rings are also free-ed in this scenario to
detect this, and suppress the "xHCI xhci_drop_endpoint called with disabled
ep ..." message in this case.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

--
Changes in v2:
Move the ring check to only guard the xhci_warn, so as to avoid side-effects
in case we have a scenario where the rings are free-ed, but the endpoint is
not yet dropped.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci.c

@@ -1673,8 +1673,10 @@ int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 	     cpu_to_le32(EP_STATE_DISABLED)) ||
 	    le32_to_cpu(ctrl_ctx->drop_flags) &
 	    xhci_get_endpoint_flag(&ep->desc)) {
-		xhci_warn(xhci, "xHCI %s called with disabled ep %p\n",
-				__func__, ep);
+		/* Do not warn when called after a usb_device_reset */
+		if (xhci->devs[udev->slot_id]->eps[ep_index].ring != NULL)
+			xhci_warn(xhci, "xHCI %s called with disabled ep %p\n",
+				  __func__, ep);
 		return 0;
 	}