From ab7a4d758b278fe44ded648e731c0638b6fa7fd3 Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Sun, 20 Sep 2020 14:23:16 +0300 Subject: [PATCH] spi: dw-dma: Move DMA transfers submission to the channels prep methods Indeed we can freely move the dmaengine_submit() method invocation and the Tx and Rx busy flag setting into the DMA Tx/Rx prepare methods. Since the Tx/Rx preparation method is now mainly used for the DMA transfers submission, here we suggest to rename it to have the _submit_{r,t}x suffix instead. By having this alteration applied first we implement another code preparation before adding the one-by-one DMA SG entries transmission, second we now have the dma_async_tx_descriptor descriptor used locally only in the new DMA transfers submission methods (this will be cleaned up a bit later), third we make the generic transfer method more readable, where now the functionality of submission, execution and wait procedures is transparently split up instead of having a preparation, intermixed submission/execution and wait procedures. Signed-off-by: Serge Semin Link: https://lore.kernel.org/r/20200920112322.24585-6-Sergey.Semin@baikalelectronics.ru Signed-off-by: Mark Brown --- drivers/spi/spi-dw-dma.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c index d2a67dee1a66..769d10ca74b4 100644 --- a/drivers/spi/spi-dw-dma.c +++ b/drivers/spi/spi-dw-dma.c @@ -272,7 +272,7 @@ static int dw_spi_dma_config_tx(struct dw_spi *dws) } static struct dma_async_tx_descriptor * -dw_spi_dma_prepare_tx(struct dw_spi *dws, struct spi_transfer *xfer) +dw_spi_dma_submit_tx(struct dw_spi *dws, struct spi_transfer *xfer) { struct dma_async_tx_descriptor *txdesc; @@ -287,6 +287,9 @@ dw_spi_dma_prepare_tx(struct dw_spi *dws, struct spi_transfer *xfer) txdesc->callback = dw_spi_dma_tx_done; txdesc->callback_param = dws; + dmaengine_submit(txdesc); + set_bit(TX_BUSY, &dws->dma_chan_busy); + return txdesc; } @@ -364,7 +367,7 @@ 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_prepare_rx(struct dw_spi *dws, +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; @@ -380,6 +383,9 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws, rxdesc->callback = dw_spi_dma_rx_done; rxdesc->callback_param = dws; + dmaengine_submit(rxdesc); + set_bit(RX_BUSY, &dws->dma_chan_busy); + return rxdesc; } @@ -426,25 +432,21 @@ static int dw_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) struct dma_async_tx_descriptor *txdesc, *rxdesc; int ret; - /* Prepare the TX dma transfer */ - txdesc = dw_spi_dma_prepare_tx(dws, xfer); + /* Submit the DMA Tx transfer */ + txdesc = dw_spi_dma_submit_tx(dws, xfer); if (!txdesc) return -EINVAL; - /* Prepare the RX dma transfer */ + /* Submit the DMA Rx transfer if required */ if (xfer->rx_buf) { - rxdesc = dw_spi_dma_prepare_rx(dws, xfer); + rxdesc = dw_spi_dma_submit_rx(dws, xfer); if (!rxdesc) return -EINVAL; /* rx must be started before tx due to spi instinct */ - set_bit(RX_BUSY, &dws->dma_chan_busy); - dmaengine_submit(rxdesc); dma_async_issue_pending(dws->rxchan); } - set_bit(TX_BUSY, &dws->dma_chan_busy); - dmaengine_submit(txdesc); dma_async_issue_pending(dws->txchan); ret = dw_spi_dma_wait(dws, xfer);