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

[Takashi Iwai]

At Mon, 20 Oct 2014 17:55:23 +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
> >
> >
> > Raymond, there can certainly be cases which this patch does not cover -
> after all, it's mostly a band aid given the lack of topology information -
> but do you see cases where this patch actually causes a *regression*? If
> so, could you point me to alsa-info for the machine where this patch causes
> a regression?
> >
> 
> www.realtek.com.tw/products/productsView.aspx?Langid=1&PNid=24&PFid=27&Level=5&Conn=4
> 
> I expect those desktop with 2+2 HD Audio codec support independent headphone
> 
> This mean the driver should not create "Lineout+HP" Playback volume
> 
> Line out and headphone cannot share same DAC

Do you have a pincfg representing this?  Then we can check it easily
via hda-emu.


Takashi