Pi3 bluetooth audio stutters with Wifi enabled

[SebastiaanAdamo]

Hello,

I'm testing with streaming music using a2dp over bluetooth on the Pi3. When Wifi is enabled, I get constant buffer underruns wit Pulseaudio (Blueman shows a downstream of around 34kB/s). As soon as I disable the Wifi interface (ifdown wlan0), the audio starts to play normally and the downstream is around 42kB/s (which is correct high quality stereo audio if I see http://soundexpert.org/news/-/blogs/bluetooth-audio-quality-a2dp).
Also tried making the buffer much larger, changing resampling type, realtime-scheduling etc. Also tried latest Pulseaudio, no difference. Seems like it is a Raspberry problem.

First thought it was because the Wifi and Bluetooth both use UART, but the is not true (and would be too slow if Wifi was over the 921600 baud if I see it correctly). They still share the same chip (BCM43438). Is there a known reason why I (and also heard others) have this problem?

[pbros]

I've been having the exact same issue. Disabling WLAN0 fixed the audio issues. However, I would very much like to be able to use the wifi...

Same is here. Took me 3 days, 2 distros to figure out it was the build in WiFi. Same error appears when i use a WiFi stick direktly at the USB Ports. When i use a USB connection cable with the USB stick everything works fine. So i simply think it comes from the build in antenna that the two 2.4 GHz services interfer each other. :-/

[pbros]

I was able to get A2DP to work by disabling the on-board wifi and using a Wi-Pi USB adapter, without any extension cable.

[Ferroin]

This brings up a rather interesting question: Does the on-board WiFi chip support Bluetooth co-existence, does the driver support this, and does it work correctly? Based on what I've seen from multiple sources, there's considerably better latency when you either disable the on-board WiFi or disable the on-board Bluetooth and use a USB adapter instead, and that sounds to me like either the on-board chip doesn't correctly implement BT co-existence, or the driver doesn't properly support it.

[pelwell]

The BCM43438 has a co-existence interface between the WiFi and Bluetooth interfaces - no software support is required.

[WayneKeenan]

@Ferroin From my experience I would say /fundamentally/ yes it does, although I'm not an authoritative source and I do not demand much on the Bluetooth side.... Whilst developing Bluetooth LE central and peripheral applications on a Pi 3 I run a VNC X session, 2x SSH sessions and have NFS share mounted all via WiFi and all are ok.

[rschulman]

+1 on this, as I've just discovered tonight. Took wlan0 down and the audio played just fine. Has anyone gotten any new word since August on what's going on here and if there's a fix?

[adn77]

+1 me too, "ifdown wlan0" and pulseaudio streams fine via a2dp

[libertineplusplus]

+1, just updated today, using an Anker Sound Core bluetooth speaker. Plays beautifully if I turn off wifi, but that's a pretty big workaround. It's annoying but workable for this project (OKAY FINE, I'll connect via hdmi instead of vncserver I GUESS ) but I too am waiting on a fix because it seriously limits my ability to make my projects mobile. VNCserver is a must.

[vgallissot]

+1 that gave me headaches finding this problem out !

I needed WiFi so I just:

1. Use a USB dongle as WiFi adapter
2. Disable onboard WiFi adapter in /etc/network/interfaces

No more sound problems.

[daryltucker]

I'm excited to see any progress on this, but as a reminder, you can Subscribe to this thread and add a reaction to the original post. It is not recommended to post a response of +1.

[jeffleus]

Agreed that no WiFi is crippling to the base Pi3. Adding a usb dongle defeats one of the big gains w/ the Pi3 of onboard WiFi/BT. :-(

[mohitkalraniit]

I have also tested the behavior and facing same issue as reported here. Planning to add additional USB WiFi adapter to overcome the problem. Hope pi would support second WiFi without much problems.