From d2b240d3d31c66df4d2da54c75ff8e27a0e006c3 Mon Sep 17 00:00:00 2001
From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Date: Sun, 8 May 2022 18:56:25 +0100
Subject: [PATCH] iio: dac: ad5421: Fix alignment for DMA safety
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Git-commit: d2b240d3d31c66df4d2da54c75ff8e27a0e006c3
Patch-mainline: v6.0-rc1
References: git-fixes
____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: 5691b23489db ("staging:iio:dac: Add AD5421 driver")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-46-jic23@kernel.org
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/iio/dac/ad5421.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/iio/dac/ad5421.c
+++ b/drivers/iio/dac/ad5421.c
@@ -70,13 +70,13 @@ struct ad5421_state {
unsigned int fault_mask;
/*
- * DMA (thus cache coherency maintenance) requires the
+ * DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
*/
union {
__be32 d32;
u8 d8[4];
- } data[2] ____cacheline_aligned;
+ } data[2] __aligned(IIO_DMA_MINALIGN);
};
static const struct iio_event_spec ad5421_current_event[] = {