Comment 0 for bug 1810636

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.

It started with Ubuntu 18.04 and continues with 18.10. I'm running . 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 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