From: Martin Sperl <[email protected]> There is a bug in the alignment checking of transfers, that results in DMA not being used for un-aligned transfers that do not cross page-boundries, which is valid.
This is due to a missconception of the meaning PAGE_MASK when implementing that check originally - (PAGE_SIZE - 1) should have been used instead. Also fixes a copy/paste error. Reported-by: <[email protected]> Signed-off-by: Martin Sperl <[email protected]> --- drivers/spi/spi-bcm2835.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 59705ab..ed74786 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -386,14 +386,14 @@ static bool bcm2835_spi_can_dma(struct spi_master *master, /* otherwise we only allow transfers within the same page * to avoid wasting time on dma_mapping when it is not practical */ - if (((size_t)tfr->tx_buf & PAGE_MASK) + tfr->len > PAGE_SIZE) { + if (((size_t)tfr->tx_buf & (PAGE_SIZE - 1)) + tfr->len > PAGE_SIZE) { dev_warn_once(&spi->dev, "Unaligned spi tx-transfer bridging page\n"); return false; } - if (((size_t)tfr->rx_buf & PAGE_MASK) + tfr->len > PAGE_SIZE) { + if (((size_t)tfr->rx_buf & (PAGE_SIZE - 1)) + tfr->len > PAGE_SIZE) { dev_warn_once(&spi->dev, - "Unaligned spi tx-transfer bridging page\n"); + "Unaligned spi rx-transfer bridging page\n"); return false; } -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
