spi: imx: fix spi resource leak with dma transfer

In spi_imx_dma_transfer(), when desc_rx = dmaengine_prep_slave_sg()
fails, the context goes to label no_dma and then return. However,
the memory allocated for desc_tx has not been freed yet, which leads
to resource leak.
Signed-off-by: NGao Pan <pandy.gao@nxp.com>
Reviewed-by: NFugang Duan <B38611@freescale.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

drivers/spi/spi-imx.c

@@ -927,7 +927,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 					tx->sgl, tx->nents, DMA_MEM_TO_DEV,
 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 		if (!desc_tx)
-			goto no_dma;
+			goto tx_nodma;
 
 		desc_tx->callback = spi_imx_dma_tx_callback;
 		desc_tx->callback_param = (void *)spi_imx;
@@ -939,7 +939,7 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 					rx->sgl, rx->nents, DMA_DEV_TO_MEM,
 					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 		if (!desc_rx)
-			goto no_dma;
+			goto rx_nodma;
 
 		desc_rx->callback = spi_imx_dma_rx_callback;
 		desc_rx->callback_param = (void *)spi_imx;
@@ -995,7 +995,9 @@ static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 
 	return ret;
 
-no_dma:
+rx_nodma:
+	dmaengine_terminate_all(master->dma_tx);
+tx_nodma:
 	pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
 		     dev_driver_string(&master->dev),
 		     dev_name(&master->dev));