Repeated keypresses from bluetooth keyboard (in Wayland sessions only)

[Matt Austin]

I have a Microsoft Surface bluetooth keyboard, and semi-frequently (e.g. around every 10-15mins) end up with repeated keypresses being made (e.g. apppppppppppt get update).

This seems to happen when the machine is under slight stress, or when a new notification pops up in gnome, so it could be related to wayland possibly - but even if wayland or other processes are causing stress, I should imagine the bluetooth hid driver should not cause repeated key presses.

Please let me know if you require further information about my environment, it's difficult to know where to begin with determining which process is the root cause of this.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: bluez 5.48-0ubuntu3.2
ProcVersionSignature: Ubuntu 5.0.0-32.34~18.04.2-generic 5.0.21
Uname: Linux 5.0.0-32-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
Date: Wed Oct 23 09:38:20 2019
InterestingModules: rfcomm bnep btusb bluetooth
MachineType: Dell Inc. Latitude 7480
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_AU.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.0.0-32-generic root=/dev/mapper/sarasota--kf--vg-root ro quiet splash vt.handoff=1
SourcePackage: bluez
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/04/2019
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 1.15.1
dmi.board.name: 00F6D3
dmi.board.vendor: Dell Inc.
dmi.board.version: A00
dmi.chassis.type: 10
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr1.15.1:bd07/04/2019:svnDellInc.:pnLatitude7480:pvr:rvnDellInc.:rn00F6D3:rvrA00:cvnDellInc.:ct10:cvr:
dmi.product.family: Latitude
dmi.product.name: Latitude 7480
dmi.product.sku: 07A0
dmi.sys.vendor: Dell Inc.
hciconfig:
 hci0: Type: Primary Bus: USB
  BD Address: F8:63:3F:E9:51:8C ACL MTU: 1021:4 SCO MTU: 96:6
  UP RUNNING PSCAN
  RX bytes:1658613 acl:66750 sco:0 events:15708 errors:0
  TX bytes:605292 acl:98 sco:0 commands:2484 errors:0

[Daniel van Vugt (vanvugt)]

Please try:

  * Logging into 'Ubuntu' instead of 'Ubuntu on Wayland'. That will mean key events are first handled by the 'Xorg' process and won't get delayed or lost by high CPU in the 'gnome-shell' process.

  * Moving away from wifi devices that might be using 2.4GHz frequencies, as they will interfere with Bluetooth and cause packet loss, and some resends. I don't know how unique the resends of lost packets are for Bluetooth keyboards...

[Matt Austin (mattaustin)]

I've now been using an Xorg session rather than Wayland and haven't seen the repeated keys issue. I do get some very nasty screen tearing when scrolling (e.g. websites) on Xorg however, so ideally I'd like to continue using Wayland.

Does that mean that this is likely a mutter bug, rather than bluez?

[Daniel van Vugt (vanvugt)]

Yes, kind of. I do know mutter's occasional stutters and pauses do cause problems for libinput in Wayland, and libinput likes to log messages warning about it. It seems likely the problem is in Mutter.

[Daniel van Vugt (vanvugt)]

BTW, please log a new bug about the screen tearing in Xorg by:

 1. Logging into 'Ubuntu' (Xorg)
 2. Opening a Terminal and run:

    ubuntu-bug mutter

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 18.04 (bionic) reached end-of-standard-support on May 31, 2023.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it anymore. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.