i2c: tegra: Fix failure during probe deferral cleanup

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>
Tested-by: Akhil R <akhilrajeev@nvidia.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index bcbbf23aa530c946749464abe0af4385e920df31..084d02a4b35b7cedb2d5d48289e502d10f17f63b 100644 (file)
--- 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;
        }