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[v2,45/92] iio: dac: ad5421: Fix alignment for DMA safety

Message ID 20220508175712.647246-46-jic23@kernel.org (mailing list archive)
State Accepted
Headers show
Series IIO: Fix alignment of buffers for DMA | expand

Commit Message

Jonathan Cameron May 8, 2022, 5:56 p.m. UTC 
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

____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@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Nuno Sá <nuno.sa@analog.com>
---
 drivers/iio/dac/ad5421.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
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Patch

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[] = {