iio: adc: ad_sigma_delta: ensure proper DMA alignment

commit 59598510be upstream.

Aligning the buffer to the L1 cache is not sufficient in some platforms
as they might have larger cacheline sizes for caches after L1 and thus,
we can't guarantee DMA safety.

That was the whole reason to introduce IIO_DMA_MINALIGN in [1]. Do the same
for the sigma_delta ADCs.

[1]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@kernel.org/

Fixes: 0fb6ee8d0b ("iio: ad_sigma_delta: Don't put SPI transfer buffer on the stack")
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240117-dev_sigma_delta_no_irq_flags-v1-1-db39261592cf@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nuno Sa 2024-01-17 13:41:03 +01:00 • committed by Greg Kroah-Hartman
commit 18cbe28671