[PATCH] spi: rockchip: fix warning of static check

[Shawn Lin <shawn.lin@rock-chips.com>]

Let's improve the check with -EPROBE_DEFER, otherwise
we may pass on null pointer to PTR_ERR. That causes the
static checker warning: passing zero to 'PTR_ERR'.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

 drivers/spi/spi-rockchip.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index bfeb0d4..2cb36d9 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -726,20 +726,24 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 	rs->dma_tx.ch = dma_request_slave_channel(rs->dev, "tx");
 	if (IS_ERR_OR_NULL(rs->dma_tx.ch)) {
 		/* Check tx to see if we need defer probing driver */
-		if (PTR_ERR(rs->dma_tx.ch) == -EPROBE_DEFER) {
+		if (rs->dma_tx.ch == ERR_PTR(-EPROBE_DEFER)) {
 			ret = -EPROBE_DEFER;
 			goto err_get_fifo_len;
 		}
 		dev_warn(rs->dev, "Failed to request TX DMA channel\n");
+		rs->dma_tx.ch = NULL;
 	}
 
 	rs->dma_rx.ch = dma_request_slave_channel(rs->dev, "rx");
-	if (!rs->dma_rx.ch) {
-		if (rs->dma_tx.ch) {
+	if (IS_ERR_OR_NULL(rs->dma_rx.ch)) {
+		if (rs->dma_tx.ch == ERR_PTR(-EPROBE_DEFER)) {
 			dma_release_channel(rs->dma_tx.ch);
 			rs->dma_tx.ch = NULL;
+			ret = -EPROBE_DEFER;
+			goto err_get_fifo_len;
 		}
 		dev_warn(rs->dev, "Failed to request RX DMA channel\n");
+		rs->dma_rx.ch = NULL;
 	}
 
 	if (rs->dma_tx.ch && rs->dma_rx.ch) {
-- 
2.3.7