[alsa-devel] Why analog loopback of sigmatel devices got removed?

[Takashi Iwai]

At Fri, 19 Jun 2009 14:36:39 +0300,
Maxim Levitsky wrote:
> 
> On Fri, 2009-06-19 at 10:23 +0200, Takashi Iwai wrote:
> > At Fri, 19 Jun 2009 11:21:41 +0300,
> > Maxim Levitsky wrote:
> > > 
> > > On Fri, 2009-06-19 at 08:32 +0200, Takashi Iwai wrote:
> > > > At Fri, 19 Jun 2009 02:50:35 +0300,
> > > > Maxim Levitsky wrote:
> > > > > 
> > > > > Hi,
> > > > > 
> > > > > Due to lack of time, I didn't update kernel on my desktop system.
> > > > > Now I notice that analog loopback go removed. Why?
> > > > 
> > > > Because it harms than helps more often.  I've got tons of bug reports
> > > > and been upset just because users blindly set "Analog Loopback" mixer
> > > > switch and lost their sound output.  This is no mixer element that
> > > > behaves intuitively -- it shuts out PCM output instead of adding the
> > > > analog loopback like other hardwares.
> > > 
> > > Here it doesn't shut PCM.
> > > I just hear input in headphones, mixed with output.
> > > I suspect that this feature might not work correctly on newer devices
> > > that ones I have added.
> > 
> > Possibly...
> 
> Probably IDT removed the analog mixer in quest for better quality.
> 
> I think it should work fine for "STAC..." parts.
> 
> Anyway lets put it back at least for my STAC9227, OK?

You can still use it just by adjusting the sysfs (and in near future
via a patch file), so I'm not going to take it back for the default.


Takashi