usb: xhci: set Input Slot Context bit in xhci_fixup_endpoint

The Renesas uPD controller is a bit more picky about validating Configure
Endpoint TRBs and requires that bit 0 of the ADD field is 1.

This is mentioned in xhci v1.2 s4.6.6.

Also drop a redundant helper function and reject invalid endpoints.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>

Author: P33M

drivers/usb/host/xhci.c

@@ -1538,10 +1538,11 @@ static int xhci_check_ep0_maxpacket(struct xhci_hcd *xhci, struct xhci_virt_devi
  * XXX: bandwidth is not recalculated. We should probably do that.
  */
 
-static unsigned int xhci_get_endpoint_flag_from_index(unsigned int ep_index)
-{
-	return 1 << (ep_index + 1);
-}
+static void xhci_setup_input_ctx_for_config_ep(struct xhci_hcd *xhci,
+		struct xhci_container_ctx *in_ctx,
+		struct xhci_container_ctx *out_ctx,
+		struct xhci_input_control_ctx *ctrl_ctx,
+		u32 add_flags, u32 drop_flags);
 
 static void xhci_fixup_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 				struct usb_host_endpoint *ep, int interval)
@@ -1555,10 +1556,14 @@ static void xhci_fixup_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 	int ret;
 	int ep_index;
 	unsigned long flags;
-	u32 ep_info_tmp;
+	u32 ep_flag, ep_info_tmp;
 
 	xhci = hcd_to_xhci(hcd);
 	ep_index = xhci_get_endpoint_index(&ep->desc);
+	ep_flag = xhci_get_endpoint_flag(&ep->desc);
+
+	if (ep_flag == SLOT_FLAG || ep_flag == EP0_FLAG)
+		return;
 
 	/* FS/LS interval translations */
 	if ((udev->speed == USB_SPEED_FULL ||
@@ -1619,8 +1624,8 @@ static void xhci_fixup_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
 		mutex_unlock(&xhci->mutex);
 		return;
 	}
-	ctrl_ctx->add_flags = xhci_get_endpoint_flag_from_index(ep_index);
-	ctrl_ctx->drop_flags = ctrl_ctx->add_flags;
+	xhci_setup_input_ctx_for_config_ep(xhci, command->in_ctx, vdev->out_ctx,
+					   ctrl_ctx, ep_flag, ep_flag);
 
 	spin_unlock_irqrestore(&xhci->lock, flags);