Package: bluez
Version: 5.50-1
Severity: normal

Dear Maintainer,

I have found that there is a significant latency in the coming button-press if 
a bluetooth joypad is inactive for more than around 3 seconds. This latency 
seem to vary up to until 500 ms. I suspect it is a driver issue because I have 
tried with multiple gamepads (8bitdo SF30 Pro and Bounabay Wee 2) and multiple 
bluetooth dongles (IOGEAR Bluetooth 4.0 USB Micro Adapter and Plugable 
USB-BT4LE USB Bluetooth 4.0 Low Energy Micro Adapter) and the issue remains 
exactly the same. I have also tried with multiple programs and the issue 
remains the same (chromium at and retroarch). However, 
the issue is not there when a controller is connected via USB.

However, I have discovered a workaround. If I connect a wireless headset that 
continuously plays audio the latency does not happen. Could the issue be that 
the driver goes into sleep mode when it has been inactive for a few seconds and 
then stops checking bluetooth signals for up to 500 ms? This would exsplain the 
headset behaiour as the headset would continuously wake up the driver.

If it matters, I used blueman-manager to pair and connect the controllers.

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
   * What was the outcome of this action?
   * What outcome did you expect instead?

*** End of the template - remove these template lines ***

-- System Information:
Debian Release: 10.0
  APT prefers testing
  APT policy: (500, 'testing')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.19.0-5-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), 
LANGUAGE=en_GB:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages bluez depends on:
ii  dbus          1.12.16-1
ii  kmod          26-1
ii  libasound2    1.1.8-1
ii  libc6         2.28-10
ii  libdbus-1-3   1.12.16-1
ii  libdw1        0.176-1.1
ii  libglib2.0-0  2.58.3-2
ii  libreadline7  7.0-5
ii  libudev1      241-5
ii  lsb-base      10.2019051400
ii  udev          241-5

bluez recommends no packages.

Versions of packages bluez suggests:
ii  pulseaudio-module-bluetooth  12.2-4

-- Configuration Files:
/etc/bluetooth/input.conf changed:

/etc/bluetooth/main.conf changed:
FastConnectable = true

-- no debconf information

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