[alsa-devel] [RFC PATCH 5/5] ASoC: omap-mcbsp: Place correct constraints for streams

[Jarkko Nikula]

On Tue, 1 Jun 2010 13:30:10 +0300
Peter Ujfalusi <peter.ujfalusi at nokia.com> wrote:

> Because, if you want to transfer in one SDMA burst more than the space free in 
> the McBSP FIFO, than where would the rest go?
> 
I would have expected peripheral to deassert the DMA request but I
haven't read the TRM so detail and experimenting with bigger period
sizes didn't work so some /dev/null effect was obviously happening :-)

> I guess it could be better than having 128 word long periods on McBSP1, 3, 4, 
> and 5. With small period size the applications also need to be woken up, but if 
> we silently handling the DMA IRQs, and the application is only woken up by every 
> 10. DMA IRQ, it might still save some power?
> 
This is worth to experiment. Probably more interrupts with or without
application wakeup reduction does not increase power as much as the
savings are from core clocks being more idle.


-- 
Jarkko