diff options
| author | Ben Nizette <bn@niasdigital.com> | 2009-12-14 22:20:20 -0800 |
|---|---|---|
| committer | Grant Likely <grant.likely@secretlab.ca> | 2009-12-17 08:57:07 -0700 |
| commit | 6aed4ee9b4610cd1e0315c90855b32e59ee81a15 (patch) | |
| tree | 5866dec5080de784cb01ce3a6426a8d4d111636e /drivers/spi | |
| parent | bec0806cfec6ded1a7e097bb95279e521a796129 (diff) | |
atmel_spi: fix dma addr calculation for len > BUFFER_SIZE
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>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | 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 f5b3fdbb1e27..8ce70cbdbb96 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) |