spi: dw-mid: follow new DMAengine workflow

Though intel-mid-dma does not follow a new DMA workflow (*) let's prepare SPI
DW driver for that.

(*) The client is obliged to call dma_async_issue_pending() which starts the
actual transfers. Old DMA drivers do not follow this, since requirement was
introduced in the discussion of [1].

[1] http://www.spinics.net/lists/arm-kernel/msg125987.html

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Andy Shevchenko 2014-10-02 16:31:09 +03:00 committed by Mark Brown
parent 2a28529944
commit f7477c2be8

View File

@ -150,7 +150,7 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
&dws->tx_sgl,
1,
DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT);
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
txdesc->callback = dw_spi_dma_done;
txdesc->callback_param = dws;
@ -172,13 +172,17 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
&dws->rx_sgl,
1,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
rxdesc->callback = dw_spi_dma_done;
rxdesc->callback_param = dws;
/* rx must be started before tx due to spi instinct */
dmaengine_submit(rxdesc);
dma_async_issue_pending(dws->rxchan);
dmaengine_submit(txdesc);
dma_async_issue_pending(dws->txchan);
return 0;
}