[Qualcomm Atheros QCA6174] sound stutters when playing on a bluetooth receiver

[Tomislav]

I can play via bluetooth from my laptop or my mobile phone. I have a set of bluetooth headphones and bluetooth speakers.

Any combination of output with the smartphone as the player works, which is as it should be.

Any combination of output with the laptop as the player is miserable: sound stutters, sometimes randomly, sometimes seemingly when I touch the laptop or come close to it...had similar or identical problems with a previous Ubuntu laptop. Bluetooth audio seems to be in very bad shape.

$ lsb_release -rd
Description: Ubuntu 18.04.4 LTS
Release: 18.04

laptop Dell XPS 9370

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: pulseaudio 1:11.1-1ubuntu7.4
ProcVersionSignature: Ubuntu 5.3.0-46.38~18.04.1-generic 5.3.18
Uname: Linux 5.3.0-46-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.14
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: tna 2174 F.... pulseaudio
 /dev/snd/pcmC0D0p: tna 2174 F...m pulseaudio
CurrentDesktop: ubuntu:GNOME
Date: Wed Apr 15 22:55:05 2020
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-xenial-amd64-20160624-2
InstallationDate: Installed on 2018-05-10 (706 days ago)
InstallationMedia: Ubuntu 16.04 "Xenial" - Build amd64 LIVE Binary 20160624-10:47
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: pulseaudio
UpgradeStatus: Upgraded to bionic on 2020-03-04 (42 days ago)
dmi.bios.date: 12/11/2019
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.12.1
dmi.board.name: 0W970W
dmi.board.vendor: Dell Inc.
dmi.board.version: A05
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.12.1:bd12/11/2019:svnDellInc.:pnXPS139370:pvr:rvnDellInc.:rn0W970W:rvrA05:cvnDellInc.:ct10:cvr:
dmi.product.family: XPS
dmi.product.name: XPS 13 9370
dmi.product.sku: 07E6
dmi.sys.vendor: Dell Inc.

[Daniel van Vugt (vanvugt)]

The main fix for Bluetooth audio stutter is one that you already have, released in pulseaudio 1:11.1-1ubuntu7.1 (bug 405294). People generally don't report problems since then so any remaining issues are likely to be hardware-specific or environment-specific.

Please run these commands:

  lsusb > lsusb.txt
  lspci -k > lspci.txt

and then attach the resulting two files.

Please also test with:

  * wifi disabled completely; and
  * using a 5GHz network instead of 2.4GHz

[Daniel van Vugt (vanvugt)]

Also I notice your kernel log mentions ath10k so bug 1746164 might be relevant.

[Tomislav (hefest)]

Adding lsusb output.

[Tomislav (hefest)]

@Daniel Thank you, will see where I get with

sudo modprobe ath10k_core btcoex_enable=1 bt_ant_diversity=1

as seems to have been suggested under the related bug.

Will try 5GHz and disabling WiFi, but the latter can obviously only be a temporary diagnostics step.

[Daniel van Vugt (vanvugt)]

It appears the same issue with the same Bluetooth chip as yours was being discussed in:

https://forum.manjaro.org/t/enabling-bluetooth-coexistence-on-ath10k-atheros-qca6174/81121

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1810636, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.