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spi: bcm2835: BUG: fix wrong use of PAGE_MASK

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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
This commit is contained in:
Martin Sperl 2015-09-10 09:32:14 +00:00 committed by Mark Brown
parent d770e558e2
commit 2a3fffd458
1 changed files with 3 additions and 3 deletions
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6
drivers/spi/spi-bcm2835.c
View file

@ -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;
}