[alsa-devel] [PATCH 0/6] snd-usb endpoint rework, version 7

[Takashi Iwai]

At Fri, 13 Apr 2012 08:19:51 +0200,
Daniel Mack wrote:
> 
> On 13.04.2012 03:39, Grant Diffey wrote:
> > On Fri, Apr 13, 2012 at 9:59 AM, Grant Diffey <gdiffey at gmail.com
> > <mailto:gdiffey at gmail.com>> wrote:
> > 
> >     On Thu, Apr 12, 2012 at 9:51 PM, Daniel Mack <zonque at gmail.com
> >     <mailto:zonque at gmail.com>> wrote:
> > 
> >         Here's the 7th iteration of patches that reimplement the
> >         streaming logic of
> >         the ALSA USB audio driver.
> > 
> >         There were some bugs reportes by Felix and Grant, which have
> >         been resolved.
> > 
> >         More testing is definitely important, but maybe the code will
> >         get a wider
> >         test coverage when merged to the development tree?
> > 
> > 
> >     So I've also tested this against the current -rt head and can report
> >     that it solves the clicking problem with playback there as well.
> > 
> >     Grant.
> 
> Good, thanks.
> 
> > so dumb question...
> > 
> > is setting a sane set of alsa controls a problem for the driver or
> > userspace/distributions?
> > 
> > the problem is.
> > 
> > if all volumes are max on module insert. the ftu is essentially unusable
> > untill they're corrected
> 
> What about alsactl? Set the mixers once, then call "alsactl store". Does
> that help?

Basically "alsactl init" then "alsactl restore" should initialize to 
a sane state.  But in the case of usb-audio, many things are still
missing.

The usb-audio driver doesn't initialize the mixer states unlike other
drivers, and alsactl init seems assuming that the mixers are all muted
/ cleared when it's called.  So, partly a problem of alsactl init.


Takashi