[PATCH v2] spi: spacemit: prepare both DMA descriptors before submitting

[kr494167 at gmail.com]

From: Surendra Singh Chouhan <kr494167 at gmail.com>

k1_spi_dma_one() currently submits the TX DMA descriptor to the DMA engine
before preparing the RX DMA descriptor. If preparing the RX descriptor
subsequently fails, the function jumps to the fallback error path without
canceling or aborting the already submitted TX DMA descriptor.

Fix this by preparing both the TX and RX descriptors before submitting
either of them to the DMA engine.

Fixes: efcd8b9d1111 ("spi: spacemit: introduce SpacemiT K1 SPI controller driver")
Reviewed-by: Alex Elder <elder at riscstar.com>
Signed-off-by: Surendra Singh Chouhan <kr494167 at gmail.com>
---
 drivers/spi/spi-spacemit-k1.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/spi/spi-spacemit-k1.c b/drivers/spi/spi-spacemit-k1.c
index 215fe66d27b4..96b41b67fcbf 100644
--- a/drivers/spi/spi-spacemit-k1.c
+++ b/drivers/spi/spi-spacemit-k1.c
@@ -278,25 +278,25 @@ static int k1_spi_dma_one(struct spi_controller *host, struct spi_device *spi,
 			  struct spi_transfer *transfer)
 {
 	struct k1_spi_driver_data *drv_data = spi_controller_get_devdata(host);
-	struct dma_async_tx_descriptor *desc;
+	struct dma_async_tx_descriptor *txdesc, *rxdesc;
 	u32 val;
 
-	/* Prepare the TX descriptor and submit it */
-	desc = k1_spi_dma_prep(drv_data, transfer, true);
-	if (!desc)
+	/* Prepare the TX descriptor */
+	txdesc = k1_spi_dma_prep(drv_data, transfer, true);
+	if (!txdesc)
 		goto fallback;
-	dmaengine_submit(desc);
 
-	/* Prepare the RX descriptor and submit it */
-	desc = k1_spi_dma_prep(drv_data, transfer, false);
-	if (!desc)
+	/* Prepare the RX descriptor */
+	rxdesc = k1_spi_dma_prep(drv_data, transfer, false);
+	if (!rxdesc)
 		goto fallback;
 
 	/* When RX is complete we also know TX has completed */
-	desc->callback = k1_spi_dma_callback;
-	desc->callback_param = drv_data;
+	rxdesc->callback = k1_spi_dma_callback;
+	rxdesc->callback_param = drv_data;
 
-	dmaengine_submit(desc);
+	dmaengine_submit(txdesc);
+	dmaengine_submit(rxdesc);
 
 	val = readl(drv_data->base + SSP_TOP_CTRL);
 	val |= TOP_TRAIL;		/* Trailing bytes handled by DMA */
-- 
2.55.0