[alsa-devel] [RFC PATCH 1/2] ALSA: hda - Fix "PCM" name being used on one DAC when there are two DACs

[Takashi Iwai]

At Sun, 19 Oct 2014 07:02:07 +0800,
Raymond Yau wrote:
> 
> > >
> > > >> >
> > > >> > In the scenario where there is one "Line Out", one "Speaker" and
> one
> > > >> > "Headphone", and there are only two DACs, two outputs will share a
> DAC.
> > > >> > Currently any mixer on such a DAC will get the "PCM" name, which is
> > > >> > misleading. Instead use "Headphone+LO" or "Speaker+LO" to better
> > > >> > specify what the volume actually controls.
> > > >>
> > > >> Are there any examples ?
> > > >>
> > > >
> > > > I used "hda-emu
> > > codecs/canonical/alc3226-dell-precision-m2800-ccert-201404-14986 -i 1"
> when
> > > developing the patches.
> > > >
> > > > I don't have any hardware available myself that exposes this behavior,
> > > but I can maybe fake one with hdajackretask, if that counts...
> > > >
> > >
> > > How about adding these names to slaves of virtual master volume/switch ?
> > >
> > > hdajackretask won't help if the topology of the codecs are  different
> > >
> > > Seem the badness still prevent the driver to support surround 5.1 with
> > > three rear panel jacks, internal speaker and front panel headphone for
> > > Thinkcenter A58 using alc662
> > >
> > >
> https://www.mail-archive.com/alsa-user@lists.sourceforge.net/msg29203.html
> > >
> > > Why 3stack desktops with 6 channels codecs not using  "Headphone+LO"  or
> > > "Speaker+LO" ?
> >
> > The problem is just the lack of DACs, so it cannot cover all three
> > outputs, no matter how the pins are chosen.  That is, it's no 6
> > channels at all but 4 channels at most.
> >
> >
> 
> http://shop.lenovo.com/us/en/desktops/thinkcentre/a-series/a58/
> 
> The technical specification of a58
> 
> 2 pin internal speaker connector
> Alc662 5.1
> 
> https://bbs.archlinux.org/viewtopic.php?id=156433
> 
> Seem windows support surround 5.1

ALC662 has three DACs, so it's a different problem, if any.
ALC269 and its variants have only two DACs.


Takashi