Bug 464022

Summary:	When hotplugging mouse/keyboard with USB switcher, input is unusable for 45 seconds
Product:	[I don't know] kde	Reporter:	Sean <sean>
Component:	general	Assignee:	Unassigned bugs mailing-list <unassigned-bugs>
Status:	RESOLVED FIXED
Severity:	normal	CC:	nate, sean
Priority:	NOR
Version:	unspecified
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
See Also:	https://bugs.kde.org/show_bug.cgi?id=435113
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Sean 2023-01-08 21:15:18 UTC

SUMMARY
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***


STEPS TO REPRODUCE
1. Unplug keyboard and mouse
2. Plug in keyboard and mouse; start timer
3. Observe that keyboard and mouse are unusable until 45 seconds pass
4. Keyboard and mouse work

OBSERVED RESULT

Keyboard and mouse are unusable for 45 seconds after hotplugging (this includes at login if using a USB switcher). After 45 seconds, keyboard and mouse are usable.

EXPECTED RESULT

Mouse and keyboard are usable immediately/shortly after hotplugging.

SOFTWARE/OS VERSIONS
Operating System: EndeavourOS
KDE Plasma Version: 5.26.5
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.8
Kernel Version: 6.1.3-arch1-1 (64-bit)
Graphics Platform: X11

ADDITIONAL INFORMATION

I ran into a similar issue like this due to https://bugs.kde.org/show_bug.cgi?id=435113. However, mouse settings are not reset after the hotplugging now; there's just a 45-second delay.

Comment 1 Sean 2023-01-08 21:31:29 UTC

After further testing, this appears to be caused due to me using a USB switcher (specifically I'm using https://www.amazon.com/gp/product/B082K87B87). What I've tried:

1. [ ] Hotplugging the mouse to the USB switcher doesn't cause any delay
2. [ ] Hotplugging the mouse directly to the PC doesn't cause any delay
3. [x] Hotplugging the USB switcher to the PC causes 45 second delay
4. [x] Hitting the switch button on USB switcher and then switching back causes 45 second delay

Note that the USB switcher itself isn't broken. This same USB switcher works fine with my macOS and Windows computers---no delay.

Comment 2 Nate Graham 2023-01-09 22:45:17 UTC

Because you're on X11, input isn't going through KWin but rather the input drives for the X11 server. Can you try on Wayland to see if it still happens? Thanks!

Comment 3 Sean 2023-01-12 04:08:47 UTC

(In reply to Nate Graham from comment #2)
> Because you're on X11, input isn't going through KWin but rather the input
> drives for the X11 server. Can you try on Wayland to see if it still
> happens? Thanks!

Confirmed that it still happens when using Wayland.

Operating System: EndeavourOS
KDE Plasma Version: 5.26.5
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.8
Kernel Version: 6.1.4-arch1-1 (64-bit)
Graphics Platform: Wayland

Comment 4 Sean 2023-01-16 20:19:09 UTC

After an update and restart yesterday/today, the issue has gone away. I'm not sure what the root cause was, but resolving anyways.