spi: rockchip: potential NULL dereference on error

We were calling dma_release_channel(rs->dma_tx.ch) when "rs->dma_tx.ch"
is potentially NULL.  There is actually a call to that in the unwind
code at the bottom of the function so we can just re-arrange this a bit
and remove the call.  Also there is no need to set rs->dma_tx.ch to
NULL on this error path.

Fixes: e4c0e06f949b ('spi: rockchip: fix probe deferral handling')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 4 insertions, 5 deletions

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 6c6c0013ec7a..cd89682065b9 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -744,10 +744,8 @@ static int rockchip_spi_probe(struct platform_device *pdev)
         rs->dma_rx.ch = dma_request_chan(rs->dev, "rx");
         if (IS_ERR(rs->dma_rx.ch)) {
                 if (PTR_ERR(rs->dma_rx.ch) == -EPROBE_DEFER) {
-                        dma_release_channel(rs->dma_tx.ch);
-                        rs->dma_tx.ch = NULL;
                         ret = -EPROBE_DEFER;
-                        goto err_get_fifo_len;
+                        goto err_free_dma_tx;
                 }
                 dev_warn(rs->dev, "Failed to request RX DMA channel\n");
                 rs->dma_rx.ch = NULL;
@@ -775,10 +773,11 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 
 err_register_master:
         pm_runtime_disable(&pdev->dev);
-        if (rs->dma_tx.ch)
-                dma_release_channel(rs->dma_tx.ch);
         if (rs->dma_rx.ch)
                 dma_release_channel(rs->dma_rx.ch);
+err_free_dma_tx:
+        if (rs->dma_tx.ch)
+                dma_release_channel(rs->dma_tx.ch);
 err_get_fifo_len:
         clk_disable_unprepare(rs->spiclk);
 err_spiclk_enable: