Merge branch 'for-4.15/alps' into for-linus

- New ALPS touchpad (T4, found currently on HP EliteBook 1000, Zbook Stduio
  and HP Elite book x360) support from Masaki Ota

1 files changed, 18 insertions, 3 deletions

diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index d1af831f43eb..68f26904c316 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -282,11 +282,26 @@ 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);
+	if (!usbhs_pipe_is_dcp(pipe)) {
+		/*
+		 * This driver checks the pipe condition first to avoid -EBUSY
+		 * from usbhsf_fifo_barrier() with about 10 msec delay in
+		 * the interrupt handler if the pipe is RX direction and empty.
+		 */
+		if (usbhs_pipe_is_dir_in(pipe))
+			ret = usbhs_pipe_is_accessible(pipe);
+		if (!ret)
+			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,