Raspberry Pi 4 - USB Audio - Weird issue

Hello,

fist thank you for this fast, lightweight and optimized KODI distro! I switched to LibreELEC from Raspbian (Raspberry OS) and I have this weird issue with my "Bose USB Audio" connected to the Raspberry under LibreELEC in KODI. Without any change, sometimes is the sound heard from the speakers, sometimes not. All you have to do is press "restart" or power it "on/off", it's like russian roulette, once it works, the second time it doesn't

I had this issue also under Raspbian, but it helped me to disable the onboard audio chip:
https://superuser.com/a/1045885/491553

And this works one year under Raspbian like a charm. Before, I tried to set up the device correctly in ALSA, but nothing works except disabling the onboard audio chip mentioned above. I tried the same in LibreELEC:

echo "blacklist snd_bcm2835" > /storage/.config/modprobe.d/blacklist.conf

but with no success, nothing change and the PI:XY sound card donť disappear.

Here is my log:

http://ix.io/2I1T

And some screenshots:

Can anyone please help me fix this issue under LibreELEC?

Hello Da Flex,

thank you for your answer. The USB Audio is USB 2.0, but I'll try it and let you know

Hello guys,

thank you for your answers. To the ghtester recommendation, unfortunately this will not help at all. When the sound is not heard, stop / start kodi will not help To the Da Flex recommendation, using the 3.0 USB port is not 100%, but significantly increased the "success" rate, mostly on "cold" start

Quote from ghtester

OK, so what if you try to unload the module:

modprobe -r snd_bcm2835

or

rmmod snd_bcm2835

Or comment out by # this line in /flash/config.txt:

dtparam=audio=on

Display More

and edited /flash/config.txt (after LibreElec restart):

Raspberry:~ # cat /flash/config.txt 
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2009-2014 Stephan Raue (stephan@openelec.tv)
# Copyright (C) 2016-present Team LibreELEC (https://libreelec.tv)
################################################################################
# Bootloader configuration - config.txt
################################################################################
#dtparam=audio=on

################################################################################
# Memory (System/GPU configuration )
################################################################################

# Default GPU memory split - at least 288M is needed for some 4k HEVC files
gpu_mem=320

################################################################################
# For overclocking and various other settings, see:
# https://www.raspberrypi.org/documentation/configuration/config-txt.md
################################################################################
# Set 'force_turbo=1' to disable dynamic overclocking and enable overclocking always.
force_turbo=0

# Force HDMI even if unplugged or powered off
# hdmi_force_hotplug=1

# Doesn't sent initial active source message.
# Avoids bringing CEC (enabled TV) out of standby and channel switch when
# rebooting.
hdmi_ignore_cec_init=1

################################################################################
# End of default configuration
################################################################################

################################################################################
# Include distribution specific config file if it exists.
################################################################################
[all]
include distroconfig.txt

but nothing changed, the sound issue is still here and PI:audio devices are still listed

Pulse audio Raspberry Os

Quote from Da Flex

I think that's a proof of my theory, so data rate is the problem, not a wrongly loaded audio driver.

My suggestion: Take another microSD and try this audio-optimized LE version. Chances are that it can handle your high audio data rate better than the stable LE.

I tried the suggested version today (specifically this build LibreELEC-RPi4.arm-9.80-nightly-20201230-c9e96e6.img.gz), but the audio behavior is the same. The interesting thing in both cases it that on cold boot (power up) audio works in most cases, but after reboot in the most of cases the audio does not work

Recently, when the Raspberry Os changed the sound backend from ALSA to PulseAudio, it was no longer necessary to turn off the internal sound card and everything works out of the box, even when powering the usb audio on while the OS is already running. Is there any plan to switch from ALSA to PulseAudio also in the LibreELEC in the future?