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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Mugilraj Dhavachelvan <dmugil2000@gmail.com>,
        =?UTF-8?q?Nuno=20S=C3=A1?= <nuno.sa@analog.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.18 0664/1095] iio: potentiometer: ad5110: Fix alignment for DMA safety
Date:   Mon, 15 Aug 2022 20:01:03 +0200
Message-Id: <20220815180456.859968072@linuxfoundation.org>
In-Reply-To: <20220815180429.240518113@linuxfoundation.org>
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From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

[ Upstream commit b5841c38cb2f7e54b0787b3e0326a6b21b89ea3e ]

____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.

Fixes: d03a74bfacce ("iio: potentiometer: Add driver support for AD5110")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Mugilraj Dhavachelvan <dmugil2000@gmail.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-81-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/potentiometer/ad5110.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/potentiometer/ad5110.c b/drivers/iio/potentiometer/ad5110.c
index d4eeedae56e5..8fbcce482989 100644
--- a/drivers/iio/potentiometer/ad5110.c
+++ b/drivers/iio/potentiometer/ad5110.c
@@ -63,10 +63,10 @@ struct ad5110_data {
 	struct mutex            lock;
 	const struct ad5110_cfg	*cfg;
 	/*
-	 * DMA (thus cache coherency maintenance) requires the
+	 * DMA (thus cache coherency maintenance) may require the
 	 * transfer buffers to live in their own cache lines.
 	 */
-	u8			buf[2] ____cacheline_aligned;
+	u8			buf[2] __aligned(IIO_DMA_MINALIGN);
 };
 
 static const struct iio_chan_spec ad5110_channels[] = {
-- 
2.35.1