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Message-Id: <20220815180454.284961537@linuxfoundation.org>
Date: Mon, 15 Aug 2022 19:59:57 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org,
Jonathan Cameron <Jonathan.Cameron@...wei.com>,
Nuno Sá <nuno.sa@...log.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.18 0598/1095] iio: adc: ad7606: Fix alignment for DMA safety
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
[ 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@...wei.com>
Acked-by: Nuno Sá <nuno.sa@...log.com>
Link: https://lore.kernel.org/r/20220508175712.647246-15-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/iio/adc/ad7606.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
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];
};
--
2.35.1
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