[alsa-devel] Headphones not detected when using Dell Dock WD15

[Takashi Iwai]

On Fri, 12 May 2017 14:29:03 +0200,
Tanu Kaskinen wrote:
> 
> On Fri, 2017-05-12 at 14:05 +0200, Takashi Iwai wrote:
> > On Fri, 12 May 2017 13:39:43 +0200,
> > Tanu Kaskinen wrote:
> > > 
> > > On Tue, 2017-05-09 at 11:00 +0200, Takashi Iwai wrote:
> > > > On Tue, 09 May 2017 10:52:56 +0200,
> > > > Sergio Villar Senin wrote:
> > > > > 
> > > > > O Mar, 09-05-2017 ás 10:37 +0200, Takashi Iwai escribiu:
> > > > > > On Tue, 09 May 2017 10:32:19 +0200,
> > > > > > Sergio Villar Senin wrote:
> > > > > > > 
> > > > > > > O Mar, 09-05-2017 ás 08:15 +0200, Takashi Iwai escribiu:
> > > > > > > > On Mon, 08 May 2017 11:34:33 +0200,
> > > > > > > > Sergio Villar Senin wrote:
> > > > > > > > > 
> > > > > > > > > Hi,
> > > > > > > > > 
> > > > > > > > > I reported this bug to pulseaudio[1] but after some
> > > > > > > > > investigation
> > > > > > > > > it
> > > > > > > > > looks like the alsa mixer is not working for the dock.
> > > > > > > > > 
> > > > > > > > > I'll be happy to provide any additional info which might be
> > > > > > > > > required
> > > > > > > > > (attaching alsa-info.sh BTW). Please add me to the Cc as I am
> > > > > > > > > not
> > > > > > > > > subscribed to this list
> > > > > > > > 
> > > > > > > > Did you try to update the dock BIOS?
> > > > > > > > The old BIOS on some Dell docks had a few known issues.
> > > > > > > 
> > > > > > > I tried with a virtual machine but the firmware update program
> > > > > > > crashes
> > > > > > > for some reason. Anyway the dock seems to be working fine because
> > > > > > > the
> > > > > > > Windows virtual machine properly detects the headphones when
> > > > > > > plugged
> > > > > > > in.
> > > > > > 
> > > > > > Well, it's a USB-audio device and it doesn't give the jack detection
> > > > > > control like HD-audio.
> > > > > 
> > > > > Not sure about the next step. Do you need additional information to
> > > > > solve the issue? Are you saying that it's a HW issue and that alsa is
> > > > > not going to provide any fix? I'm a bit confused.
> > > > 
> > > > In general Linux USB-audio driver doesn't provide the jack detection
> > > > control.  If any, it's vendor-specific.
> > > 
> > > The problem is not just that jack detection doesn't work, the problem
> > > is that the mixer doesn't work at all:
> > > 
> > > $ amixer -c1
> > > amixer: Mixer hw:1 load error: Invalid argument
> > 
> > Did you try to upgrade the firmware?  At least that kind of error
> > could be solved by the newer firmware.
> 
> According to Sergio's earlier mail, the firmware has not been
> successfully updated, so I guess at this point we can blame the
> firmware.
> 
> > > I would expect the USB-audio driver to provide a mixer control for
> > > choosing the routing, unless that's implemented in some non-standard
> > > way too. As it stands, PulseAudio has no control over the routing, so
> > > the headphone output apparently can't be used at all.
> > 
> > Hrm it's not clear to me.  The routing among which?
> 
> After I sent my previous mail, I realized that I've been assuming that
> only the rear output (speakers) of the dock works, and the front output
> (headphones) doesn't, but Sergio never actually said that. So I was
> talking about routing between the rear and front outputs, but now I'm
> not sure if that's the problem after all.

AFAIK, there is no routing selection in the device but only the mute /
volume controls.  Realtek people told me that the non-working output
(one of headphone or line-out) is likely the firmware bug.

Actually, this might be worked around by not touching any mute /
volume control.  Writing some value screws the firmware, as it seems.


Takashi