iio: frequency: adf4350: 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.

Updated help text to 'may' require buffers to be in their own cacheline.

Fixes: e31166f0fd ("iio: frequency: New driver for Analog Devices ADF4350/ADF4351 Wideband Synthesizers")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-67-jic23@kernel.org
This commit is contained in:
Jonathan Cameron 2022-05-08 18:56:46 +01:00
parent 8ff2eb625c
commit 389b8972eb

View File

@ -56,10 +56,10 @@ struct adf4350_state {
*/
struct mutex lock;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
* DMA (thus cache coherency maintenance) may require that
* transfer buffers live in their own cache lines.
*/
__be32 val ____cacheline_aligned;
__be32 val __aligned(IIO_DMA_MINALIGN);
};
static struct adf4350_platform_data default_pdata = {