This is a note to let you know that I've just added the patch titled
spi: bcm2835: BUG: fix wrong use of PAGE_MASK
to the 4.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-bcm2835-bug-fix-wrong-use-of-page_mask.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 2a3fffd45822070309bcf0b1e1dae624d633824a Mon Sep 17 00:00:00 2001
From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Date: Thu, 10 Sep 2015 09:32:14 +0000
Subject: spi: bcm2835: BUG: fix wrong use of PAGE_MASK
From: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
commit 2a3fffd45822070309bcf0b1e1dae624d633824a upstream.
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@xxxxxxxxxxx>
Signed-off-by: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi-bcm2835.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/spi/spi-bcm2835.c
+++ b/drivers/spi/spi-bcm2835.c
@@ -386,14 +386,14 @@ static bool bcm2835_spi_can_dma(struct s
/* 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;
}
Patches currently in stable-queue which might be from kernel@xxxxxxxxxxxxxxxx are
queue-4.2/spi-bcm2835-bug-fix-wrong-use-of-page_mask.patch
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