On Tue, Jul 16, 2013 at 11:07:07AM +0200, Lars-Peter Clausen wrote:
I would assume that most of them don't express hardware limitations but rather are sensible lower limits which allow operation without over-/underruns. But that's something that doesn't necessarily depend on the
Yes, indeed. Or just cut'n'pasted from some other driver without much thought.
DMA controller, but rather on the system as a whole, e.g. on a slower machine you'd typically set the limit higher so the CPU has a better chance to keep up. So this isn't something you'd want to set in the DMA controller driver. But I'm not sure if there is a good way to calculate a sensible minimum buffer size based on the whole system's constraints.
Not really. It's going to depend on userspace as well, and things like SMIs on systems with those.