spi: imx: Fix freeing of DMA channels if spi_bitbang_start() fails

If the SPI controller has has_dmamode = true and spi_bitbang_start() fails
in spi_imx_probe(), then the driver must release the DMA channels acquired
in spi_imx_sdma_init() by calling spi_imx_sdma_exit() in the fail path.

Fixes: f62caccd ("spi: spi-imx: add DMA support")
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Robin Gong <b38343@freescale.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Link: https://lore.kernel.org/r/20201005132229.513119-1-marex@denx.deSigned-off-by: NMark Brown <broonie@kernel.org>

drivers/spi/spi-imx.c

@@ -1707,7 +1707,7 @@ static int spi_imx_probe(struct platform_device *pdev)
 	ret = spi_bitbang_start(&spi_imx->bitbang);
 	if (ret) {
 		dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
-		goto out_runtime_pm_put;
+		goto out_bitbang_start;
 	}
 
 	dev_info(&pdev->dev, "probed\n");
@@ -1717,6 +1717,9 @@ static int spi_imx_probe(struct platform_device *pdev)
 
 	return ret;
 
+out_bitbang_start:
+	if (spi_imx->devtype_data->has_dmamode)
+		spi_imx_sdma_exit(spi_imx);
 out_runtime_pm_put:
 	pm_runtime_dont_use_autosuspend(spi_imx->dev);
 	pm_runtime_put_sync(spi_imx->dev);