[PATCH 5.19 0712/1157] iio: potentiometer: mcp41010: Fix alignment for DMA safety

From: Greg Kroah-Hartman
Date: Tue Aug 16 2022 - 00:35:10 EST


From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

[ Upstream commit c5f78f4d2168ba21324095b0d46d4353c2eace4d ]

____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: 092cb71a604e ("iio: potentiometer: Add driver for Microchip MCP41xxx/42xxx")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220508175712.647246-84-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/iio/potentiometer/mcp41010.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/potentiometer/mcp41010.c b/drivers/iio/potentiometer/mcp41010.c
index 30a4594d4e11..2b73c7540209 100644
--- a/drivers/iio/potentiometer/mcp41010.c
+++ b/drivers/iio/potentiometer/mcp41010.c
@@ -60,7 +60,7 @@ struct mcp41010_data {
const struct mcp41010_cfg *cfg;
struct mutex lock; /* Protect write sequences */
unsigned int value[MCP41010_MAX_WIPERS]; /* Cache wiper values */
- u8 buf[2] ____cacheline_aligned;
+ u8 buf[2] __aligned(IIO_DMA_MINALIGN);
};

#define MCP41010_CHANNEL(ch) { \
--
2.35.1