Ok, I managed to get the latest firmware working. It still exhibits the same issue. I think I must of only rebooted last time instead of shutting down completely.
I've tried the speaker sitting on top of the track-pad, about 50 cm away from the laptop - all to the same effect - the it's like it misses an audio packet, and rather than dropping the packet, it re-transmits again, buffering all subsequent packets for the stream. I would rather lose the packets completely in this case. The speaker is a Sony SRS-HG1. I can pair the speaker to my Xiaomi Mi8 phone and it negotiates LDAC codec for the Bluetooth audio sink. I can then run high load on the Mi8 WiFi and play a movie in FullHD over DLNA and it never skips a beat, there is a small delay as you'd expect with Bluetooth, but it's less than 100 ms and seems normal after a short while. I experienced this problem also in another location when I was house sitting recently - so different environment/access points etc. I think demonstrating the problem with the speaker and my phone without any problems puts me back on the firmware/driver troubleshooting path. Do you have any other ideas @kaihengfeng? Would you like me to do Bluetooth packet capture? -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1810636 Title: QCA6174 doesn't utilise btcoex - Ubuntu 18 Bluetooth Audio Skip/Stutter/Delay WiFi bandwidth conflict Dell XPS 9570 Status in linux package in Ubuntu: Confirmed Bug description: I'm running Linux 4.20.0-042000-generic #201812232030 x64 on a Dell XPS 9570 with QCA6174 chipset, and have had the problem with Bluetooth audio choppiness ever since I have owned this laptop. This problem has persisted for me with previous kernels. If I disable wifi and use media on machine locally, the problem doesn't occur. Note: I've reverted back v4.18.0-13-generic and reproduced the problem for the apport-collect report. It started with Ubuntu 18.04 and continues with 18.10. It's particularly noticeable when the when saturating the WLAN connection with throughput, i.e. copying a large file sequentially across from a samba share, but also streaming video online results in the audio progressively delaying over-time. Re-establishing the Bluetooth audio sync restores the sync, but slowly creeps out again. I've upgraded my linux-firmware package to disco 176 to match v4.20 kernel drivers ref: https://launchpad.net/ubuntu/+source/linux- firmware/1.176 The ath10k_core driver that supports this device has a reference for btcoex: ref https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/ath/ath10k/core.c?h=v4.20#n2598 It's possible that the Bluetooth component firmware is not supporting or communicating btcoex compatibility, but this is starting to reach the edge of my ability to diagnose the problem. This btcoex support in ath9k has resolved/improved the Bluetooth bandwidth problem for older Qualcomm chipsets as shown in https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1746164 As a troubleshooting step, I've also tried the very latest firmware-6 file from, but I'm continuing to experience the problem ref: https://github.com/kvalo/ath10k-firmware/tree/master/QCA6174/hw3.0/4.4.1 --- ProblemType: Bug ApportVersion: 2.20.10-0ubuntu13.1 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: berg 2871 F.... pulseaudio CurrentDesktop: GNOME DistroRelease: Ubuntu 18.10 InstallationDate: Installed on 2018-07-02 (187 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) MachineType: Dell Inc. XPS 15 9570 Package: linux (not installed) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_AU.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.18.0-13-generic root=UUID=c825a7b0-a5ac-41de-bd57-7663fef8a1f1 ro quiet splash vt.handoff=1 ProcVersionSignature: Ubuntu 4.18.0-13.14-generic 4.18.17 RelatedPackageVersions: linux-restricted-modules-4.18.0-13-generic N/A linux-backports-modules-4.18.0-13-generic N/A linux-firmware 1.176 Tags: cosmic Uname: Linux 4.18.0-13-generic x86_64 UpgradeStatus: Upgraded to cosmic on 2018-10-18 (79 days ago) UserGroups: adm cdrom dip libvirt lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 11/02/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: 1.6.0 dmi.board.name: 07GHH0 dmi.board.vendor: Dell Inc. dmi.board.version: A00 dmi.chassis.type: 10 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvr1.6.0:bd11/02/2018:svnDellInc.:pnXPS159570:pvr:rvnDellInc.:rn07GHH0:rvrA00:cvnDellInc.:ct10:cvr: dmi.product.family: XPS dmi.product.name: XPS 15 9570 dmi.product.sku: 087C dmi.sys.vendor: Dell Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1810636/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
