This is a note to let you know that I've just added the patch titled
iio: adc: ad7606: 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-adc-ad7606-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 a62d1156743230595b873265f4791e7ebacce290
Author: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Date: Sun May 8 18:55:54 2022 +0100
iio: adc: ad7606: Fix alignment for DMA safety
[ Upstream commit 6268c6eebb13f228d418f9adaca848b3ed5b3cf9 ]
____cacheline_aligned is an insufficient guarantee for non-coherent DMA
on platforms with 128 byte cachelines above L1. Switch to the updated
IIO_ALIGN definition.
Update the comment to reflect the fact DMA safety 'may' require
separate cachelines.
Fixes: 7989b4bb23fe ("iio: adc: ad7616: Add support for AD7616 ADC")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220508175712.647246-15-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 4f82d7c9acfd..2dc4f599f9df 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -116,11 +116,11 @@ struct ad7606_state {
struct completion completion;
/*
- * DMA (thus cache coherency maintenance) requires the
+ * DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
* 16 * 16-bit samples + 64-bit timestamp
*/
- unsigned short data[20] ____cacheline_aligned;
+ unsigned short data[20] __aligned(IIO_DMA_MINALIGN);
__be16 d16[2];
};
