Re: audio output via DP/hdmi over jack only after restarting xserver?

Thanks Paul,
all seems to work now.

Thanks Robin,
interestingly I did not experience drop-outs or xruns so far.

best, P

* Paul Davis <[email protected]> [2026-05-27 01:48]:
> try -d alsa -dhw:0,3
>=20
> On Tue, May 26, 2026 at 4:29=E2=80=AFPM Peter P. <peterparker@fastmail.=
com> wrote:
>=20
> > Hi list,
> >
> > I sometimes connect a miniDisplayPort to HDMI adaptor with an X230
> > thinkpad. In order to output audio via this connection using jack I h=
ave
> > to restart my Xserver (means: logging out and back into X).
> >
> > Here is how I am trying to debug this, first listing the respective
> > output (card 0, device 0):
> > $ aplay -l
> > **** List of PLAYBACK Hardware Devices ****
> > card 0: PCH [HDA Intel PCH], device 0: ALC269VC Analog [ALC269VC Anal=
og]
> >   Subdevices: 1/1
> >   Subdevice #0: subdevice #0
> > card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
> >   Subdevices: 0/1
> >   Subdevice #0: subdevice #0
> > card 0: PCH [HDA Intel PCH], device 7: HDMI 1 [HDMI 1]
> >   Subdevices: 1/1
> >   Subdevice #0: subdevice #0
> > card 0: PCH [HDA Intel PCH], device 8: HDMI 2 [HDMI 2]
> >
> > I can start jackd with this output, its options being
> > $ jackd -v -t2000 -dalsa -dhw:0 -r48000 -p512 -n3 -Xseq -D -Phw:PCH,3=
 -i2
> > -o2
> > although there is no monitor connected to this output.
> >
> > $ cat /proc/asound/card0/pcm3p/sub0/status
> > shows the device as running after jackd start.
> >
> > Next step: Connecting an external HDMI monitor via a miniDisplayPort
> > adapter to the
> > laptop, this makes xrandr show that HDMI1 is connected.
> >
> > Enabling the monitor output via xrandr will make aplay -l lists the
> > monitor model as well:
> > card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [DELL U2410]
> >
> > Playing back audio will not output sound.
> > If I exit my Xsession and log back in, while jackd keeps running, aud=
io
> > output suddenly works, and I have no idea why.
> >
> > I often have to switch back and forth between HDMI audio and other
> > outputs but having to log out and back into X is quite cumbersome.
> >
> > If anyone has any ideas how I can got about debugging/fixing this
> > further, I'd be glad to hear!
> >
> > best, Peter
> >