spi: bcm2835: BUG: fix wrong use of PAGE_MASK

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: <robert@axium.co.nz>
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c
index 59705ab23577494b68a136ca0f3c377b3371ca2b..ed74786e68cbc62cf8eddae463e23d8af272f286 100644 (file)
--- 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;
        }