usb: renesas_usbhs: fix the BCLR setting condition for non-DCP pipe

BugLink: http://bugs.launchpad.net/bugs/1724783

commit 6124607a upstream.

This patch fixes an issue that the driver sets the BCLR bit of
{C,Dn}FIFOCTR register to 1 even when it's non-DCP pipe and
the FRDY bit of {C,Dn}FIFOCTR register is set to 1.

Fixes: e8d548d5 ("usb: renesas_usbhs: fifo became independent from pipe.")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

drivers/usb/renesas_usbhs/fifo.c

@@ -285,11 +285,17 @@ static void usbhsf_fifo_clear(struct usbhs_pipe *pipe,
 			      struct usbhs_fifo *fifo)
 {
 	struct usbhs_priv *priv = usbhs_pipe_to_priv(pipe);
+	int ret = 0;
 
 	if (!usbhs_pipe_is_dcp(pipe))
-		usbhsf_fifo_barrier(priv, fifo);
+		ret = usbhsf_fifo_barrier(priv, fifo);
 
-	usbhs_write(priv, fifo->ctr, BCLR);
+	/*
+	 * if non-DCP pipe, this driver should set BCLR when
+	 * usbhsf_fifo_barrier() returns 0.
+	 */
+	if (!ret)
+		usbhs_write(priv, fifo->ctr, BCLR);
 }
 
 static int usbhsf_fifo_rcv_len(struct usbhs_priv *priv,