[PATCH 5.18 0643/1095] iio: dac: ltc2688: Fix alignment for DMA safety
From: Greg Kroah-Hartman
Date: Mon Aug 15 2022 - 17:42:08 EST
From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
[ Upstream commit 2030708377a219b548a9a36da57d3852382baf1d ]
____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: 832cb9eeb931 ("iio: dac: add support for ltc2688")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Acked-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220508175712.647246-60-jic23@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/iio/dac/ltc2688.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/dac/ltc2688.c b/drivers/iio/dac/ltc2688.c
index 2f9c384885f4..04ec38b1cad1 100644
--- a/drivers/iio/dac/ltc2688.c
+++ b/drivers/iio/dac/ltc2688.c
@@ -91,10 +91,10 @@ struct ltc2688_state {
struct mutex lock;
int vref;
/*
- * 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 tx_data[6] ____cacheline_aligned;
+ u8 tx_data[6] __aligned(IIO_DMA_MINALIGN);
u8 rx_data[3];
};
--
2.35.1