Intermittent keyboard lag with Tecknet EKB01002BK01 keyboard

[Rob Somerville]

This bug manifests itself slightly differently across different scenarios. To summarise, scrolling through a long file/directory listing in Midnight Commander (e.g. > 40 items) causes the cursor to lag, stutter and pause.

In 23.10 if the up/down key is depressed there is a delay of about 0.25 seconds before moving onto the previous/next item. In 24.04, the cursor will stick on the previous/last item until it is released.

This behavior is not exhibited in a console session [e.g. via Ctrl+Alt+F5], with Ubuntu 22.04 LTS or under Wayland. It also does not seem to affect the Tecknet EMK01707 keyboard under Ubuntu 23.10.

This behavior has been observed using both Guake terminal [Version 3.10] and Gnome terminal [Version 3.52.0 for GNOME 46].

[Affected Ubuntu versions]

Ubuntu 23.10
Ubuntu 24.04

[To recreate]

Open mc in terminal and browse through a long directory/file listing (> 40 items). This behavior will manifest immediately or after a few cycles.

[Expected behavior]

The cursor should scroll linearly throughout a list without pauses, juddering, lag or requiring the user to release the key.

[Workarounds]

1. Switch to Wayland
2. Use a different keyboard. The problem was not apparent using a Tecknet EMK01707 keyboard under 23.10, however this has not been tested under Noble Numbat.

[Further information]

MC version:

GNU Midnight Commander 4.8.30
Built with GLib 2.80.0
Built with S-Lang 2.3.3 with terminfo database
Built with libssh2 1.11.0
With builtin Editor and Aspell support
With subshell support as default
With support for background operations
With mouse support on xterm and Linux console
With support for X11 events
With internationalization support
With multiple codepages support
With ext2fs attributes support
Virtual File Systems:
 cpiofs, tarfs, sfs, extfs, ext2undelfs, ftpfs, sftpfs, fish
Data types:
 char: 8; int: 32; long: 64; void *: 64; size_t: 64; off_t: 64;

[Related bugs]

This seems related to https://bugs.launchpad.net/debian/+source/xserver-xorg-input-evdev/+bug/1002951

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: xorg 1:7.7+23ubuntu2
ProcVersionSignature: Ubuntu 6.8.0-22.22-generic 6.8.1
Uname: Linux 6.8.0-22-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
.proc.driver.nvidia.capabilities.fabric-imex-mgmt:
 DeviceFileMinor: 4323
 DeviceFileMode: 256
 DeviceFileModify: 1
.proc.driver.nvidia.capabilities.gpu0: Error: path was not a regular file.
.proc.driver.nvidia.capabilities.mig: Error: path was not a regular file.
.proc.driver.nvidia.gpus.0000.06.00.0: Error: path was not a regular file.
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.suspend: suspend hibernate resume
.proc.driver.nvidia.suspend_depth: default modeset uvm
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 550.67 Tue Mar 12 23:54:15 UTC 2024
 GCC version: gcc version 13.2.0 (Ubuntu 13.2.0-23ubuntu3)
ApportVersion: 2.28.0-0ubuntu1
Architecture: amd64
BootLog: Error: [Errno 13] Permission denied: '/var/log/boot.log'
CasperMD5CheckResult: pass
CompositorRunning: None
CurrentDesktop: ubuntu:GNOME
Date: Thu Apr 11 19:11:20 2024
DistUpgraded: Fresh install
DistroCodename: noble
DistroVariant: ubuntu
DkmsStatus: nvidia/550.67, 6.8.0-22-generic, x86_64: installed
ExtraDebuggingInterest: Yes
GraphicsCard:
 NVIDIA Corporation GM206 [GeForce GTX 960] [10de:1401] (rev a1) (prog-if 00 [VGA controller])
   Subsystem: ZOTAC International (MCO) Ltd. GM206 [GeForce GTX 960] [19da:2375]
InstallationDate: Installed on 2024-04-10 (1 days ago)
InstallationMedia: Ubuntu 24.04 LTS "Noble Numbat" - Beta amd64 (20240410)
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
ProcEnviron:
 LANG=en_GB.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-6.8.0-22-generic root=/dev/mapper/ubuntu--vg-ubuntu--lv ro quiet splash vt.handoff=7
SourcePackage: xorg
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 07/16/2020
dmi.bios.release: 5.14
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P4.00
dmi.board.name: A320M-DVS R4.0
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP4.00:bd07/16/2020:br5.14:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnA320M-DVSR4.0:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:skuToBeFilledByO.E.M.:
dmi.product.family: To Be Filled By O.E.M.
dmi.product.name: To Be Filled By O.E.M.
dmi.product.sku: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.120-2
version.libgl1-mesa-dri: libgl1-mesa-dri 24.0.3-1ubuntu4
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:21.1.11-2ubuntu1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:22.0.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20210115-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.17-2build1

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 2059847, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.