spi: dw-dma: Remove DMA Tx-desc passing around

It's pointless to pass the Rx and Tx transfers DMA Tx-descriptors, since
they are used in the Tx/Rx submit method only. Instead just return the
submission status from these methods. This alteration will make the code
less complex.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Link: https://lore.kernel.org/r/20200920112322.24585-8-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 aa39008..9f70818 100644 (file)
--- a/drivers/spi/spi-dw-dma.c
+++ b/drivers/spi/spi-dw-dma.c
@@ -271,8 +271,7 @@ static int dw_spi_dma_config_tx(struct dw_spi *dws)
        return dmaengine_slave_config(dws->txchan, &txconf);
 }
 
-static struct dma_async_tx_descriptor *
-dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer)
+static int dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer)
 {
        struct dma_async_tx_descriptor *txdesc;
        dma_cookie_t cookie;
@@ -284,7 +283,7 @@ dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer)
                                DMA_MEM_TO_DEV,
                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!txdesc)
-               return NULL;
+               return -ENOMEM;
 
        txdesc->callback = dw_spi_dma_tx_done;
        txdesc->callback_param = dws;
@@ -293,12 +292,12 @@ dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer)
        ret = dma_submit_error(cookie);
        if (ret) {
                dmaengine_terminate_sync(dws->txchan);
-               return NULL;
+               return ret;
        }
 
        set_bit(TX_BUSY, &dws->dma_chan_busy);
 
-       return txdesc;
+       return 0;
 }
 
 static inline bool dw_spi_dma_rx_busy(struct dw_spi *dws)
@@ -375,8 +374,7 @@ static int dw_spi_dma_config_rx(struct dw_spi *dws)
        return dmaengine_slave_config(dws->rxchan, &rxconf);
 }
 
-static struct dma_async_tx_descriptor *dw_spi_dma_submit_rx(struct dw_spi *dws,
-               struct spi_transfer *xfer)
+static int dw_spi_dma_submit_rx(struct dw_spi *dws, struct spi_transfer *xfer)
 {
        struct dma_async_tx_descriptor *rxdesc;
        dma_cookie_t cookie;
@@ -388,7 +386,7 @@ static struct dma_async_tx_descriptor *dw_spi_dma_submit_rx(struct dw_spi *dws,
                                DMA_DEV_TO_MEM,
                                DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
        if (!rxdesc)
-               return NULL;
+               return -ENOMEM;
 
        rxdesc->callback = dw_spi_dma_rx_done;
        rxdesc->callback_param = dws;
@@ -397,12 +395,12 @@ static struct dma_async_tx_descriptor *dw_spi_dma_submit_rx(struct dw_spi *dws,
        ret = dma_submit_error(cookie);
        if (ret) {
                dmaengine_terminate_sync(dws->rxchan);
-               return NULL;
+               return ret;
        }
 
        set_bit(RX_BUSY, &dws->dma_chan_busy);
 
-       return rxdesc;
+       return 0;
 }
 
 static int dw_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
@@ -445,19 +443,18 @@ static int dw_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
 
 static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
 {
-       struct dma_async_tx_descriptor *txdesc, *rxdesc;
        int ret;
 
        /* Submit the DMA Tx transfer */
-       txdesc = dw_spi_dma_submit_tx(dws, xfer);
-       if (!txdesc)
-               return -EINVAL;
+       ret = dw_spi_dma_submit_tx(dws, xfer);
+       if (ret)
+               return ret;
 
        /* Submit the DMA Rx transfer if required */
        if (xfer->rx_buf) {
-               rxdesc = dw_spi_dma_submit_rx(dws, xfer);
-               if (!rxdesc)
-                       return -EINVAL;
+               ret = dw_spi_dma_submit_rx(dws, xfer);
+               if (ret)
+                       return ret;
 
                /* rx must be started before tx due to spi instinct */
                dma_async_issue_pending(dws->rxchan);