On Fri, Jul 23, 2021 at 06:44:04PM +0100, Jonathan Cameron wrote: > Mark Brown <broonie@xxxxxxxxxx> wrote: > > > @Mark. This has come up a few times recently. Are we now safe to assume > > > that regmap will always copy data when used with SPI and hence we no > > > longer need to ensure DMA safe buffers? > > Only for single register I/O, I'd not assume that for things like raw > > I/O. > Thanks for the confirmation. So in this driver that means we > need DMA safe buffers for the regmap_bulk_ calls. Easiest approach > is probably to use a __cacheline_aligned buffer at the end of the > iio_priv() structure. Yeah, it might be fine depending on the bus/format type but it's not something you can generally assume.
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