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authorQipan Li <Qipan.Li@csr.com>2014-04-14 08:30:01 +0200
committerMark Brown <broonie@linaro.org>2014-04-14 22:04:59 +0200
commitbf83fd6402a856eeb9a22c364c50ccf9bbdf9b17 (patch)
tree905fe272f9d08fff5e4483294b8e96c6b26e59e6 /drivers/spi/spi-sirf.c
parentspi: sirf: fix line over 80 characters style issue (diff)
downloadlinux-bf83fd6402a856eeb9a22c364c50ccf9bbdf9b17.tar.xz
linux-bf83fd6402a856eeb9a22c364c50ccf9bbdf9b17.zip
spi: sirf: fix spi full-duplex DMA transferring issue
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>
Diffstat (limited to 'drivers/spi/spi-sirf.c')
-rw-r--r--drivers/spi/spi-sirf.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/drivers/spi/spi-sirf.c b/drivers/spi/spi-sirf.c
index 3c12f396d96a..0c039d4542a5 100644
--- a/drivers/spi/spi-sirf.c
+++ b/drivers/spi/spi-sirf.c
@@ -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);