[PATCH] usb: renesas_usbhs: Add error handling for usbhsf_fifo_select()

[Wentao Liang <vulab@iscas.ac.cn>]

In usbhsf_dcp_data_stage_prepare_pop(), the return value of
usbhsf_fifo_select() needs to be checked. A proper implementation
can be found in usbhsf_dma_try_pop_with_rx_irq().

Add an error check and jump to PIO pop when FIFO selection fails.

Fixes: 9e74d601de8a ("usb: gadget: renesas_usbhs: add data/status stage handler")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 drivers/usb/renesas_usbhs/fifo.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/renesas_usbhs/fifo.c b/drivers/usb/renesas_usbhs/fifo.c
index 10607e273879..6cc07ab4782d 100644
--- a/drivers/usb/renesas_usbhs/fifo.c
+++ b/drivers/usb/renesas_usbhs/fifo.c
@@ -466,6 +466,7 @@ static int usbhsf_dcp_data_stage_prepare_pop(struct usbhs_pkt *pkt,
 	struct usbhs_pipe *pipe = pkt->pipe;
 	struct usbhs_priv *priv = usbhs_pipe_to_priv(pipe);
 	struct usbhs_fifo *fifo = usbhsf_get_cfifo(priv);
+	int ret;
 
 	if (usbhs_pipe_is_busy(pipe))
 		return 0;
@@ -480,10 +481,14 @@ static int usbhsf_dcp_data_stage_prepare_pop(struct usbhs_pkt *pkt,
 
 	usbhs_pipe_sequence_data1(pipe); /* DATA1 */
 
-	usbhsf_fifo_select(pipe, fifo, 0);
+	ret = usbhsf_fifo_select(pipe, fifo, 0);
+	if (ret < 0)
+		goto usbhsf_pio_prepare_pop;
+
 	usbhsf_fifo_clear(pipe, fifo);
 	usbhsf_fifo_unselect(pipe, fifo);
 
+usbhsf_pio_prepare_pop:
 	/*
 	 * change handler to PIO pop
 	 */
-- 
2.42.0.windows.2