[PATCH v2] i2c: tegra: Fix failure during probe deferral cleanup

[Thierry Reding <thierry.reding@gmail.com>]

From: Thierry Reding <treding@nvidia.com>

If the driver fails to obtain a DMA channel, it will initiate cleanup
and try to release the DMA channel that couldn't be retrieved. This will
cause a crash because the cleanup will try to dereference an ERR_PTR()-
encoded error code.

However, there's nothing to clean up at this point yet, so we can avoid
this by simply resetting the DMA channel to NULL instead of storing the
error code.

Fixes: fcc8a89a1c83 ("i2c: tegra: Share same DMA channel for RX and TX")
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
Changes in v2:
- simplify patch by setting dma_chan = NULL on channel request failure

 drivers/i2c/busses/i2c-tegra.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index f155e9028f94..2a13f11edfd1 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -460,6 +460,7 @@ static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev)
 	i2c_dev->dma_chan = dma_request_chan(i2c_dev->dev, "tx");
 	if (IS_ERR(i2c_dev->dma_chan)) {
 		err = PTR_ERR(i2c_dev->dma_chan);
+		i2c_dev->dma_chan = NULL;
 		goto err_out;
 	}
 
-- 
2.41.0