On Fri, 23 Jul 2021 18:14:22 +0100 Mark Brown <broonie@xxxxxxxxxx> wrote: > On Fri, Jul 23, 2021 at 06:10:22PM +0100, Jonathan Cameron 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. > > Note that my name is spelt Mark. > I'll blame Friday. Thanks, Jonathan