[LAD] Headless RME HDSP/HDSPM mixer settings

[Adrian Knoth]

On Tue, Nov 19, 2013 at 10:26:08PM +0000, Fons Adriaensen wrote:

> > I wrote a quick&dirty cmdline tool to dump and restore the internal
> > mixer state of an RME card (no matter if handled by snd_hdsp or
> > snd_hdspm, so this should apply to almost all RME cards except the new
> > MADIFX).
> 
> Moment...
> 
> For years I've believed that it is not possible to read the
> current state of the mixer, and that this is the reason why
> hdspmixer can't show it when started. Is this wrong, or is
> something else going on here ?


Well, it's a bit of everything. You cannot read the current mixer state
from the card (as in: hardware), so the driver caches these values, and
that's what the tool is dumping.


hdspmixer could do the same but has an additional problem: while the
mixer state is simply a matrix of shorts, hdspmixer has the notion of
"mute" and "solo" buttons, which of course get combined into the
appropriate matrix entries. If read back, solo/mute would be lost and
would have to be shown as "volume 0" and "some volume > 0". Probably
enough for the average case, so yes, there's no need for hdspmixer to
load its default setting every time it starts, thus ruining the current
mixer state.



Cheers

-- 
mail: adi at thur.de  	http://adi.thur.de	PGP/GPG: key via keyserver