No Audio through USB-C DP mode

hello am using edge-lxde-ubuntu. i have tried hdmi and it works fine with audio present. but the with USB-C DP alt mode i get the image fine but no audio. i checked the pulseaudio settings and there are no more option to mingle with. the output devices shows HDMI-DP and SPDIF devices and the configuration tap shows two devices both set to “Stereo-output” i can change either of them to “multichannel output” or “off” . when i chose multichannel for any of them, pulseaudio server stopped working and wont relaunch again. i can only get back working by editing /usr/shared/pulse/alsamixer/profiles/default.conf and removing the fallback option from multichannel template.

please advice!

please help with a lead before i give up on linux … pulse audio is a nightmare

Can you share more detail of the USB device that you used? And a photo to show the connection between the USB-C and the audio device will be helpful for us.

am using “Pepper jobs
ExtendTouch portable screen” for usb-c video and audio.

ill attach pictures and i used the proper usb-c port and cable.

am sorry if i confused you… am using USB-C DP ALT MODE! (which is supposed to stream both video and audio) … it works perfectly in android but not in linux (only video in linux)

This is a fresh edge-lubuntu distro from your repo!
If I change to multichannel option , pulseaudio stops working.
I think pulse audio thinks its an analogue output . And why both HDMI and DP are only one output not two separate outputs ?

Please test with any portable screen you have. And yes this screen has speakers. When I use the normal HDMI port on screen audio works

this is the contents of my ~/.config/pulse/ file :

#!/usr/bin/pulseaudio -nF

This file is part of PulseAudio.

PulseAudio is free software; you can redistribute it and/or modify it

under the terms of the GNU Lesser General Public License as published by

the Free Software Foundation; either version 2 of the License, or

(at your option) any later version.

PulseAudio is distributed in the hope that it will be useful, but

WITHOUT ANY WARRANTY; without even the implied warranty of


General Public License for more details.

You should have received a copy of the GNU Lesser General Public License

along with PulseAudio; if not, see

This startup script is used only if PulseAudio is started per-user

(i.e. not in system mode)


Automatically restore the volume of streams and devices

load-module module-device-restore
load-module module-stream-restore
load-module module-card-restore

Automatically augment property information from .desktop files

stored in /usr/share/application

load-module module-augment-properties

Should be after module--restore but before module--detect

load-module module-switch-on-port-available

Use hot-plugged devices like Bluetooth or USB automatically (LP: #1702794)

load-module module-switch-on-connect

Load audio drivers statically

(it’s probably better to not load these drivers manually, but instead

use module-udev-detect – see below – for doing this automatically)

#load-module module-alsa-sink
#load-module module-alsa-source device=hw:1,0
#load-module module-oss device="/dev/dsp" sink_name=output source_name=input
#load-module module-oss-mmap device="/dev/dsp" sink_name=output source_name=input
#load-module module-null-sink
#load-module module-pipe-sink

Automatically load driver modules depending on the hardware available

load-module module-udev-detect

Use the static hardware detection module (for systems that lack udev support)

load-module module-detect

Automatically connect sink and source if JACK server is present

load-module module-jackdbus-detect channels=2

Automatically load driver modules for Bluetooth hardware

load-module module-bluetooth-policy

load-module module-bluetooth-discover

Load several protocols

load-module module-esound-protocol-unix
load-module module-native-protocol-unix

Network access (may be configured with paprefs, so leave this commented

here if you plan to use paprefs)

#load-module module-esound-protocol-tcp
#load-module module-native-protocol-tcp
#load-module module-zeroconf-publish

Load the RTP receiver module (also configured via paprefs, see above)

#load-module module-rtp-recv

Load the RTP sender module (also configured via paprefs, see above)

#load-module module-null-sink sink_name=rtp format=s16be channels=2 rate=44100 sink_properties=“device.description=‘RTP Multicast Sink’”
#load-module module-rtp-send source=rtp.monitor

Load additional modules from GConf settings. This can be configured with the paprefs tool.

Please keep in mind that the modules configured by paprefs might conflict with manually

loaded modules.

load-module module-gconf

Automatically restore the default sink/source when changed by the user

during runtime

NOTE: This should be loaded as early as possible so that subsequent modules

that look up the default sink/source get the right value

load-module module-default-device-restore

Automatically move streams to the default sink if the sink they are

connected to dies, similar for sources

load-module module-rescue-streams

Make sure we always have a sink around, even if it is a null sink.

load-module module-always-sink

Honour intended role device property

load-module module-intended-roles

Automatically suspend sinks/sources that become idle for too long

load-module module-suspend-on-idle

If autoexit on idle is enabled we want to make sure we only quit

when no local session needs us anymore.

load-module module-console-kit
load-module module-systemd-login

Enable positioned event sounds

load-module module-position-event-sounds

Cork music/video streams when a phone stream is active

load-module module-role-cork

Modules to allow autoloading of filters (such as echo cancellation)

on demand. module-filter-heuristics tries to determine what filters

make sense, and module-filter-apply does the heavy-lifting of

loading modules and rerouting streams.

load-module module-filter-heuristics
load-module module-filter-apply

Make some devices default

#set-default-sink output
#set-default-source input

Set default sink to HDMI

set-default-sink alsa_output.platform-hdmi-dp-sound.stereo-fallback

Update sink name

update-sink-proplist alsa_output.platform-hdmi-dp-sound.stereo-fallback device.description=HDMI-DP-Output
#update-sink-proplist alsa_output.platform-rt5651-sound.HiFi__hw_realtekrt5651co__sink device.description=RT5651-CODEC-Output
update-sink-proplist alsa_output.platform-spdif-sound.stereo-fallback device.description=SPDIF-Output

Umm hello? It’s been 3 days since I replied … Help please

khadas team. would u help plz?

did anyone run into this problem? am thinking of moving to manjaro

Khadas team is on Labour Day holidays they will be back on 6th.

Also You might not be able to use USC-D audio yet on Manjaro, As there are no USB-C audio out drivers yet.

@goenjoy Please following up this.

@numbqq Please following up this.

@Spikerguy not even usb-c display on this manjaro :frowning:

@numbqq isn’t this considered a major issue here ? No one want to look at it? This is a media box after all. We need audio

Hello @Qali-Buds

Have you select the sound card in the top right corner?

Hey just saw this.

There is no support for usb-c alt mode on amlogix devices on arm it is not available on rockchip rk3399 too yet.

Ayufan have worked on a patch but they will never be upstreamed while for edge devices khadas will have to patch the dts to support usb-c otg, pd and alt-mode (dp).

We have it patched for pinebookpro audio is not ready as it will take time to work on audio out over usb-c alt mode.