xhci: Always restore EP_SOFT_CLEAR_TOGGLE even if ep reset failed

Some device drivers call libusb_clear_halt when target ep queue
is not empty. (eg. spice client connected to qemu for usb redir)

Before commit f5249461 ("xhci: Clear the host side toggle
manually when endpoint is soft reset"), that works well.
But now, we got the error log:

    EP not empty, refuse reset

xhci_endpoint_reset failed and left ep_state's EP_SOFT_CLEAR_TOGGLE
bit still set

So all the subsequent urb sumbits to the ep will fail with the
warn log:

    Can't enqueue URB while manually clearing toggle

We need to clear ep_state EP_SOFT_CLEAR_TOGGLE bit after
xhci_endpoint_reset, even if it failed.

Fixes: f5249461 ("xhci: Clear the host side toggle manually when endpoint is soft reset")
Cc: stable <stable@vger.kernel.org> # v4.17+
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200821091549.20556-4-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci.c

@@ -3236,10 +3236,11 @@ static void xhci_endpoint_reset(struct usb_hcd *hcd,
 
 	wait_for_completion(cfg_cmd->completion);
 
-	ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
 	xhci_free_command(xhci, cfg_cmd);
 cleanup:
 	xhci_free_command(xhci, stop_cmd);
+	if (ep->ep_state & EP_SOFT_CLEAR_TOGGLE)
+		ep->ep_state &= ~EP_SOFT_CLEAR_TOGGLE;
 }
 
 static int xhci_check_streams_endpoint(struct xhci_hcd *xhci,