spi: dw-dma: Check DMA Tx-desc submission status

We suggest to add the dmaengine_submit() return value test for errors.  It
has been unnecessary while the driver was expected to be utilized in pair
with DW DMAC. But since now the driver can be used with any DMA engine, it
might be useful to track the errors on DMA submissions so not miss them
and get into an unpredictable driver behaviour.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112322.24585-7-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c
index 769d10ca74b41e65a8d9cd860ca454f40b83e5c5..aa39008091261e9d0ff58be0fbb0ce80b7af6410 100644 (file)
--- a/drivers/spi/spi-dw-dma.c
+++ b/drivers/spi/spi-dw-dma.c
@@ -275,6 +275,8 @@ static struct dma_async_tx_descriptor *
 dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer)
 {
        struct dma_async_tx_descriptor *txdesc;
+       dma_cookie_t cookie;
+       int ret;
 
        txdesc = dmaengine_prep_slave_sg(dws->txchan,
                                xfer->tx_sg.sgl,
@@ -287,7 +289,13 @@ dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer)
        txdesc->callback = dw_spi_dma_tx_done;
        txdesc->callback_param = dws;
 
-       dmaengine_submit(txdesc);
+       cookie = dmaengine_submit(txdesc);
+       ret = dma_submit_error(cookie);
+       if (ret) {
+               dmaengine_terminate_sync(dws->txchan);
+               return NULL;
+       }
+
        set_bit(TX_BUSY, &dws->dma_chan_busy);
 
        return txdesc;
@@ -371,6 +379,8 @@ static struct dma_async_tx_descriptor *dw_spi_dma_submit_rx(struct dw_spi *dws,
                struct spi_transfer *xfer)
 {
        struct dma_async_tx_descriptor *rxdesc;
+       dma_cookie_t cookie;
+       int ret;
 
        rxdesc = dmaengine_prep_slave_sg(dws->rxchan,
                                xfer->rx_sg.sgl,
@@ -383,7 +393,13 @@ static struct dma_async_tx_descriptor *dw_spi_dma_submit_rx(struct dw_spi *dws,
        rxdesc->callback = dw_spi_dma_rx_done;
        rxdesc->callback_param = dws;
 
-       dmaengine_submit(rxdesc);
+       cookie = dmaengine_submit(rxdesc);
+       ret = dma_submit_error(cookie);
+       if (ret) {
+               dmaengine_terminate_sync(dws->rxchan);
+               return NULL;
+       }
+
        set_bit(RX_BUSY, &dws->dma_chan_busy);
 
        return rxdesc;