[PATCH 5.19 0709/1157] iio: potentiometer: ad5110: Fix alignment for DMA safety

Greg Kroah-Hartman
2022-08-16T04:36:22Z

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