From: Qipan Li Date: Mon, 14 Apr 2014 06:30:01 +0000 (+0800) Subject: spi: sirf: fix spi full-duplex DMA transferring issue X-Git-Tag: firefly_0821_release~176^2~3735^2~2^5~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bf83fd6402a856eeb9a22c364c50ccf9bbdf9b17;p=firefly-linux-kernel-4.4.55.git 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 Signed-off-by: Barry Song Signed-off-by: Mark Brown --- 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);