Bug 514741

Summary:	No device notifications unless device directly plugged into laptop
Product:	[Plasma] plasmashell	Reporter:	farblos <farblos>
Component:	Notifications	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	kde, notmart
Priority:	NOR
Version First Reported In:	master
Target Milestone:	1.0
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description farblos 2026-01-17 14:25:26 UTC

SUMMARY

I have a Dell Latitude 7420 laptop running the OS/KDE environments listed below.

In both environments, I can see (and hear) device notifications when plugging in a, say, keyboard *directly* into the one USB-A port of the laptop. However, if I plug the same device through some USB hub or the Dell WD-19 TB3 dock, I do not get any notifications, neither the sound nor the toast. Regardless of not getting the notification, I still can use the device after plugging it, so hub and dock should work OK.

STEPS TO REPRODUCE

1. Plug in keyboard through USB hub attached to laptop.

OBSERVED RESULT

No device notification.

EXPECTED RESULT

Get device notification.

SOFTWARE/OS VERSIONS

openSUSE Krypton with latest KDE (live):

--------------------------------------------------
Operating System: openSUSE Tumbleweed 20260113
KDE Plasma Version: 6.6.80
KDE Frameworks Version: 6.23.0
Qt Version: 6.10.1
Kernel Version: 6.18.5-1-default (64-bit)
Graphics Platform: X11
Processors: 8 × 11th Gen Intel® Core™ i7-1185G7 @ 3.00GHz
Memory: 32 GiB of RAM (31.1 GiB usable)
Graphics Processor: Mesa Intel® Iris® Xe Graphics
--------------------------------------------------

Debian Trixie (installed):

--------------------------------------------------
Operating System: Debian GNU/Linux 13
KDE Plasma Version: 6.3.6
KDE Frameworks Version: 6.13.0
Qt Version: 6.8.2
Kernel Version: 6.12.63+deb13-amd64 (64-bit)
Graphics Platform: Wayland
Processors: 8 × 11th Gen Intel® Core™ i7-1185G7 @ 3.00GHz
Memory: 32 GiB of RAM (31.1 GiB usable)
Graphics Processor: Mesa Intel® Iris® Xe Graphics
Manufacturer: Dell Inc.
Product Name: Latitude 7420
--------------------------------------------------

ADDITIONAL INFORMATION

I tried debugging kded with gdb, but I got lost in the C++, TBH. If you can give me hints on where the udev events (?) would be transformed into device notifications (?) I could take a closer look. Building KDE/Plasma from scratch is not feasible due to device constraints.

Comment 1 Marco Martin 2026-01-20 10:08:25 UTC

I can't quite reproduce, even tough i don't have that laptop or dock, device notifications work fine form usb docks

Comment 2 farblos 2026-01-20 21:12:51 UTC

Thanks for testing.  I'm glad I have tested with a fresh, live system, because this issue seems so ... strange.

Anyway, I tested (with the live system) on another laptop, same result.  I'll try with a desktop tomorrow.

Below is what "udevadm monitor" dumps for the plug of a mouse.  As previously, a "direct plug" gives a notification while a "hub plug" does not.

------------------------- direct plug -------------------------
KERNEL[171.135112] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3 (usb)
KERNEL[171.137822] change   /devices/pci0000:00/0000:00:14.0/usb3/3-3 (usb)
KERNEL[171.137955] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0 (usb)
KERNEL[171.141696] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D (hid)
KERNEL[171.141814] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/input/input51 (input)
KERNEL[171.141932] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/input/input51/mouse0 (input)
KERNEL[171.141982] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/input/input51/event1 (input)
KERNEL[171.142059] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/hidraw/hidraw0 (hidraw)
KERNEL[171.142113] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D (hid)
KERNEL[171.142164] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0 (usb)
KERNEL[171.142222] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-3 (usb)
UDEV  [171.145897] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3 (usb)
UDEV  [171.147828] change   /devices/pci0000:00/0000:00:14.0/usb3/3-3 (usb)
UDEV  [171.149699] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0 (usb)
UDEV  [171.151120] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D (hid)
UDEV  [171.153463] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/input/input51 (input)
UDEV  [171.156144] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/input/input51/mouse0 (input)
UDEV  [171.158396] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/hidraw/hidraw0 (hidraw)
UDEV  [171.284045] add      /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D/input/input51/event1 (input)
UDEV  [171.285503] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/0003:046D:C001.001D (hid)
UDEV  [171.287133] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0 (usb)
UDEV  [171.290820] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-3 (usb)
------------------------- direct plug -------------------------

------------------------- hub plug -------------------------
KERNEL[268.798690] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3 (usb)
KERNEL[268.802142] change   /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3 (usb)
KERNEL[268.802195] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0 (usb)
KERNEL[268.806276] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E (hid)
KERNEL[268.806377] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/input/input52 (input)
KERNEL[268.806487] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/input/input52/mouse0 (input)
KERNEL[268.806550] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/input/input52/event1 (input)
KERNEL[268.806591] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/hidraw/hidraw0 (hidraw)
KERNEL[268.806643] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E (hid)
KERNEL[268.806692] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0 (usb)
KERNEL[268.806739] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3 (usb)
UDEV  [268.810624] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3 (usb)
UDEV  [268.812725] change   /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3 (usb)
UDEV  [268.814550] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0 (usb)
UDEV  [268.814984] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E (hid)
UDEV  [268.815902] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/input/input52 (input)
UDEV  [268.817238] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/input/input52/mouse0 (input)
UDEV  [268.819352] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/hidraw/hidraw0 (hidraw)
UDEV  [268.939884] add      /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E/input/input52/event1 (input)
UDEV  [268.942530] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0/0003:046D:C001.001E (hid)
UDEV  [268.944032] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3/3-1.3:1.0 (usb)
UDEV  [268.945413] bind     /devices/pci0000:00/0000:00:14.0/usb3/3-1/3-1.3 (usb)
------------------------- hub plug -------------------------

Does that look similarly on your box?  In particular, do you also get one additional level in the device path for a hub plug?

Comment 3 farblos 2026-01-21 20:32:27 UTC

Hm.  Using the openSUSE Krypton live system I tested now three laptops (all behaving as decribed in the first post), one medium-aged desktop (also behaving as decribed in the first post), and one very old desktop, which did not gave any notifications whatsover.

If you cannot reproduce the issue on your end, probably you can give me hints where/how to inspect this issue with gdb?  For example, the following would be interesting:

- Where does the notification mechanism register for the udev events?

- How could I set breakpoints in the notification manager that break only on udev events?

- Any general KDE-with-GDB advise or pointers.

As mentioned previously, I cannot build KDE due to resource constraints.

Thanks!