Commit 20307083 authored by Jonathan Cameron's avatar Jonathan Cameron
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iio: dac: ltc2688: 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: 832cb9ee ("iio: dac: add support for ltc2688")
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: default avatarNuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-60-jic23@kernel.org
parent 1c20292c

drivers/iio/dac/ltc2688.c

+2 −2
Original line number Diff line number Diff line
@@ -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];

};