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Message-Id: <20220815180505.785360769@linuxfoundation.org>
Date: Mon, 15 Aug 2022 20:00:07 +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>,
Michael Hennerich <michael.hennerich@...log.com>,
Nuno Sá <nuno.sa@...log.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.19 0651/1157] iio: adc: ltc2497: Fix alignment for DMA safety
From: Jonathan Cameron <Jonathan.Cameron@...wei.com>
[ Upstream commit 6ebf401d555ee1e75e779b865d38e171db0aa1f2 ]
____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: bc82222fcca1 ("iio:adc: Driver for Linear Technology LTC2497 ADC")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
Cc: Michael Hennerich <michael.hennerich@...log.com>
Acked-by: Nuno Sá <nuno.sa@...log.com>
Link: https://lore.kernel.org/r/20220508175712.647246-23-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/iio/adc/ltc2497.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c
index 1adddf5a88a9..f7c786f37ceb 100644
--- a/drivers/iio/adc/ltc2497.c
+++ b/drivers/iio/adc/ltc2497.c
@@ -20,10 +20,10 @@ struct ltc2497_driverdata {
struct ltc2497core_driverdata common_ddata;
struct i2c_client *client;
/*
- * DMA (thus cache coherency maintenance) requires the
+ * DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
*/
- __be32 buf ____cacheline_aligned;
+ __be32 buf __aligned(IIO_DMA_MINALIGN);
};
static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata,
--
2.35.1
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