[PATCH 2/4] spi: atmel-quadspi: Fix printed error code during DMA setup

[Krzysztof Kozlowski]

On dma_request_chan() failure driver NULL-ifies the 'rx_chan' and
immediately uses it as PTR_ERR() so dev_err_probe() prints incorrect
error code.  Rework the code so proper error code will be printed and
NULL-ifying of 'rx_chan' will happen in common error handling block
(failure of DMA setup is not fatal for the driver and further code
depends on 'rx_chan' being non-NULL for DMA operations).

Reported by Smatch:
  drivers/spi/atmel-quadspi.c:1287 atmel_qspi_dma_init() warn: passing zero to 'PTR_ERR'

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski at linaro.org>
---
 drivers/spi/atmel-quadspi.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index d135cca4e454..057bc20a74ce 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -1283,9 +1283,9 @@ static int atmel_qspi_dma_init(struct spi_controller *ctrl)
 
 	aq->rx_chan = dma_request_chan(&aq->pdev->dev, "rx");
 	if (IS_ERR(aq->rx_chan)) {
-		aq->rx_chan = NULL;
-		return dev_err_probe(&aq->pdev->dev, PTR_ERR(aq->rx_chan),
-				     "RX DMA channel is not available\n");
+		ret = dev_err_probe(&aq->pdev->dev, PTR_ERR(aq->rx_chan),
+				    "RX DMA channel is not available\n");
+		goto null_rx_chan;
 	}
 
 	aq->tx_chan = dma_request_chan(&aq->pdev->dev, "tx");
@@ -1306,8 +1306,9 @@ static int atmel_qspi_dma_init(struct spi_controller *ctrl)
 
 release_rx_chan:
 	dma_release_channel(aq->rx_chan);
-	aq->rx_chan = NULL;
 	aq->tx_chan = NULL;
+null_rx_chan:
+	aq->rx_chan = NULL;
 	return ret;
 }
 
-- 
2.43.0