iio: dac: ad5755: Fix alignment for DMA safety

____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: c499d029d8 ("iio:dac: Add ad5755 driver")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-51-jic23@kernel.org
This commit is contained in:
Jonathan Cameron 2022-05-08 18:56:30 +01:00
parent 444e38927d
commit d0c167ceff

View file

@ -189,14 +189,14 @@ struct ad5755_state {
struct mutex lock;
/*
* 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);
};
enum ad5755_type {