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>
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@ -189,14 +189,14 @@ static void atmel_spi_next_xfer_data(struct spi_master *master,
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/* use scratch buffer only when rx or tx data is unspecified */
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if (xfer->rx_buf)
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*rx_dma = xfer->rx_dma + xfer->len - len;
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*rx_dma = xfer->rx_dma + xfer->len - *plen;
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else {
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*rx_dma = as->buffer_dma;
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if (len > BUFFER_SIZE)
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len = BUFFER_SIZE;
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}
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if (xfer->tx_buf)
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*tx_dma = xfer->tx_dma + xfer->len - len;
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*tx_dma = xfer->tx_dma + xfer->len - *plen;
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else {
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*tx_dma = as->buffer_dma;
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if (len > BUFFER_SIZE)
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