Weird behavior after installing pulseaudio-module-bluetooth.

[Izzi]

TL;DR: Framerate capped at 50 after installing pulseaudio-module-bluetooth. Removing the package doesn't solve the problem. Only fix seems to be re-flashing a new image.

I searched around to see if anyone noticed it before and found nothing. I stumbled upon a really weird behavior after installing pulseaudio-module-bluetooth for pairing bluetooth speakers. (I followed this guide).

The audio works flawlessly, but after the installation, all my games begun to run at around 48~50 fps when I could get a smooth 60fps before.

I'm running a Raspberry Pi 4 model with the latest 4.6 image, arm clock at 1.9Ghz and gpu clock at 750Mhz. The power supply is adequate (CanaKit, even checked using vcgencmd get_throttled, output was 0x0) and thermals are completely fine (caps around 60º under load using the Flirc case).

I tried to mess around with NTSC/PAL configs to see if it was the case, I purged the package from the system and undid all the file changes, nothing solved the problem. Only way to fix it is by backing everything up and re-flashing the image again.

I can consistently reproduce the problem doing:

1. Flash the 4.6 image
2. Run some games to measure framerate
3. Run the bluetooth guide linked above
4. Run the same games and compare framerate

Expected behavior:
Same framerate as before installing pulseaudio-module-bluetooth (60 fps with vsync on)

Actual behavior:
Framerate seems to float around 48~50 fps with vsync on.

Roms used for testing:
Mario Kart (snes), Link's Awakening (gbc), Mega Man Zero (gba) and Rival Schools Arcade Disc (psx)
All run at 60fps before installation, 50fps after.

[mitu]

Can you get an emulator log (/dev/shm/runcommand.log) captured with verbose logging ? Post it to pastebin.com.
What does tvservice -s shows ?

[Izzi]

@mitu Yeah, but I'll have to make you wait a little, I'm currently at work, will get the logs as soon as I clock out.

[Izzi]

@mitu

Sorry by the delay in response.

Before installing pulseaudio-module-bluetooth and setting it up:

tvservice -s outputs state 0xa [HDMI CUSTOM RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive
runcommand.log verbose output: https://pastebin.com/2ycTusDv

After installing:
tvservice -s outputs the same thing state 0xa [HDMI CUSTOM RGB lim 16:9], 1920x1080 @ 60.00Hz, progressive
rincommand.log verbose output: https://pastebin.com/TUv7C3vk

What I noticed this time, is that just installing the package doesn't cause the problem, I had to edit both /etc/pulse/default.pa and /etc/bluetooth/main.conf as stated in the guide for the problem to appear, and after that, reverting the changes does not resolve them.

[mitu]

Thanks for providing the log file. I don't notice anything different between the 2 runs, so it's not something related to a configuration.
Try removing pulseaudio completely then reboot the system, this might get rid of any PA interference.