This is a note to let you know that I've just added the patch titled
iio: dac: ad5421: Fix alignment for DMA safety
to the 5.18-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:
iio-dac-ad5421-fix-alignment-for-dma-safety.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 99d52f47f794431ac904bb2380f7915cd5a1aecb
Author: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Date: Sun May 8 18:56:25 2022 +0100
iio: dac: ad5421: Fix alignment for DMA safety
[ Upstream commit d2b240d3d31c66df4d2da54c75ff8e27a0e006c3 ]
____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1. Switch to the updated
IIO_DMA_MINALIGN definition.
Update the comment to include 'may'.
Fixes: 5691b23489db ("staging:iio:dac: Add AD5421 driver")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220508175712.647246-46-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iio/dac/ad5421.c b/drivers/iio/dac/ad5421.c
index eedf661d32b2..7644acfd879e 100644
--- a/drivers/iio/dac/ad5421.c
+++ b/drivers/iio/dac/ad5421.c
@@ -72,13 +72,13 @@ struct ad5421_state {
struct mutex lock;
/*
- * DMA (thus cache coherency maintenance) requires the
+ * DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
*/
union {
__be32 d32;
u8 d8[4];
- } data[2] ____cacheline_aligned;
+ } data[2] __aligned(IIO_DMA_MINALIGN);
};
static const struct iio_event_spec ad5421_current_event[] = {
