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spi: sirf: fix spi full-duplex DMA transferring issue

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sometimes t->tx can be equal with t->rx. for example, spidev will make
tx and rx point to spidev->buffer at the same time. currently, for this
case, we map the buffer BIDIRECTION to fix the cache consistency.

Signed-off-by: Qipan Li <Qipan.Li@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Qipan Li 2014-04-14 14:30:01 +08:00 committed by Mark Brown
parent d77ec5df47
commit bf83fd6402
1 changed files with 5 additions and 2 deletions
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7
drivers/spi/spi-sirf.c
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@ -383,7 +383,8 @@ static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
struct dma_async_tx_descriptor *rx_desc, *tx_desc;
sspi->dst_start = dma_map_single(&spi->dev,
sspi->rx, t->len, DMA_FROM_DEVICE);
sspi->rx, t->len, (t->tx_buf != t->rx_buf) ?
DMA_FROM_DEVICE : DMA_BIDIRECTIONAL);
rx_desc = dmaengine_prep_slave_single(sspi->rx_chan,
sspi->dst_start, t->len, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
@ -391,7 +392,9 @@ static int spi_sirfsoc_transfer(struct spi_device *spi, struct spi_transfer *t)
rx_desc->callback_param = &sspi->rx_done;
sspi->src_start = dma_map_single(&spi->dev,
(void *)sspi->tx, t->len, DMA_TO_DEVICE);
(void *)sspi->tx, t->len,
(t->tx_buf != t->rx_buf) ?
DMA_TO_DEVICE : DMA_BIDIRECTIONAL);
tx_desc = dmaengine_prep_slave_single(sspi->tx_chan,
sspi->src_start, t->len, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);