Messages in this thread Patch in this message | | | Subject | [PATCH] atmel_spi: fix dma addr calculation for len > BUFFER_SIZE | From | Ben Nizette <> | Date | Sun, 27 Sep 2009 15:26:27 +1000 |
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If len > BUFFER_LEN and !xfer->rx_buf we end up calculating the tx buffer address as
*tx_dma = xfer->tx_dma + xfer->len - BUFFER_SIZE;
which is constant; i.e. we just send the last BUFFER_SIZE data over again until we've reached the right number of bytes.
This patch gets around this by using the /requested/ length when calculating addresses.
Note there's no way len != *plen when we calculate the rx buffer address but conceptually we should be using *plen and I don't want someone to come through later, see the calculations for rx and tx are different and "clean up" back to what we had.
Signed-off-by: Ben Nizette <bn@niasdigital.com>
--- drivers/spi/atmel_spi.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index f5b3fdb..8ce70cb 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -189,14 +189,14 @@ static void atmel_spi_next_xfer_data(struct spi_master *master, /* use scratch buffer only when rx or tx data is unspecified */ if (xfer->rx_buf) - *rx_dma = xfer->rx_dma + xfer->len - len; + *rx_dma = xfer->rx_dma + xfer->len - *plen; else { *rx_dma = as->buffer_dma; if (len > BUFFER_SIZE) len = BUFFER_SIZE; } if (xfer->tx_buf) - *tx_dma = xfer->tx_dma + xfer->len - len; + *tx_dma = xfer->tx_dma + xfer->len - *plen; else { *tx_dma = as->buffer_dma; if (len > BUFFER_SIZE) -- 1.6.0.4
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