[CentOS] Mate and USB headphones

Sat Jan 7 23:34:37 UTC 2017
Fred Smith <fredex at fcshome.stoneham.ma.us>

On Sat, Jan 07, 2017 at 02:11:47PM -0800, Alice Wonder wrote:
> On 01/07/2017 01:42 PM, Laurent CREPET wrote:
> >On Sat, Jan 7, 2017 at 10:23 PM, Alice Wonder <alice at domblogger.net> wrote:
> >
> >>Logitech H540 headphones were working fine.
> >>
> >>Suddenly stopped.

On my C7 Mate system I have what may be the same issue:
if the "sound preferences" app (aka Mate Volume Control) is already
running at the time the USB headphones are plugged in, the USB phones
appear as disabled.

OTOH, if the phones are plugged in, then the Mate Volume Control is
started, they are not listed as disabled.

When that first began happening (a year or two ago, I think) I
posted on the Mate forums and someone said he thought he saw the
bug and would do a build to fix it.  unfortunately his build did not
fix it, and it has remained.

AFAIK, I have no sound hardware blacklisted (where do you blacklist it?)
I have an Nvidia card with HDMI output, and it shows up in the sound
app, but since I don't do HDMI video on this machine I always just 
ignore that device.
> >>
> >>
> >Maybe a stupid question, but did you try your headphones on another
> >computer?
> >Is the device listed in the ouput of command "lsusb"?
> >
> I got that to work.
> I had to remove the blacklist for the useless Intel HD audio on the
> video card that CentOS 7 likes to pick by default even though the
> video card doesn't have an audio out except HDMI - but with that
> driver allowed, the audio system reset and the USB headphones are no
> longer listed as disabled.
> There has to be a better way and there needs to be a way to enable a
> device that is listed as disabled for unknown reasons, serious UI
> issue.
> I don't understand why the sound control panel doesn't allow one to
> enable a device it has listed as disabled.
> The disabled kernel module was for Intel HD which is NOT what the
> USB headphones uses, and it works fine with that kernel module
> disabled, it just wouldn't let me enable the headphones after
> whatever disabled them disabled them.

---- Fred Smith -- fredex at fcshome.stoneham.ma.us -----------------------------
                       I can do all things through Christ 
                              who strengthens me.
------------------------------ Philippians 4:13 -------------------------------