Bug 503430

Created attachment 180700 [details]
An Archive Of Unprocessed Performance Data After Connection

SUMMARY

Connecting my smartphone to my PC causes filesystem slowdown for all KDE applications I've tried. That is, Dolphin, Gwenview, and the File Picker KDE Portal (via Gittyup's Flatpak). This behaviour is new.

STEPS TO REPRODUCE

To reproduce the exact configuration I have (IDK how much applies):

1. Connect a SITECOM CN-386 4-port USB-C hub to the MB's TB4 port.
2. Connect a XAOSUN TB4 cable to the hub.
3. Connect a Fairphone 5 5G to the cable. On my smartphone, I have USB debugging enabled.

OBSERVED RESULT

Every application which interacts with the filesystem slows to an unreasonable amount.

EXPECTED RESULT

It shouldn't slow. It never did, until now.

SOFTWARE/OS VERSIONS

I've explicitly verified that this *affects* `xdg-desktop-portal-kde-6.3.4-2.fc42.x86_64`, `dolphin-25.04.0-3.fc42.x86_64`, and `gwenview-25.04.0-2.fc42.x86_64` (and, strangely, `android-tools-35.0.2-3.fc42.x86_64` and `sudo-1.9.15-7.p5.fc42.x86_64`). The DE and OS are undermentioned:

> Operating System: Fedora Linux 42
> KDE Plasma Version: 6.3.4
> KDE Frameworks Version: 6.13.0
> Qt Version: 6.9.0
> Kernel Version: 6.14.3-300.fc42.x86_64 (64-bit)
> Graphics Platform: Wayland

> Manufacturer: ASRock
> Product Name: X670E Taichi

I've also verified that this *doesn't* affect `xdg-desktop-portal-gtk-1.15.3-1.fc42.x86_64`.

ADDITIONAL INFORMATION

I'll add some files with the undermentioned data contained:

> .
> ├── Flamegraphs
> │   ├── bad-adb.avif
> │   ├── bad-dolphin.avif
> │   ├── bad-gwenview.avif
> │   ├── good-adb.avif
> │   ├── good-dolphin.avif
> │   └── good-gwenview.avif
> └── Performance Data
>     ├── Processed
>     │   ├── bad-adb.data.perfparser
>     │   ├── bad-dolphin.data.perfparser
>     │   ├── bad-gwenview.data.perfparser
>     │   ├── good-adb.data.perfparser
>     │   ├── good-dolphin.data.perfparser
>     │   └── good-gwenview.data.perfparser
>     └── Unprocessed
>         ├── bad-adb.data
>         ├── bad-dolphin.data
>         ├── bad-gwenview.data
>         ├── good-adb.data
>         ├── good-dolphin.data
>         └── good-gwenview.data
> 
> 5 directories, 18 files

This was originally reported at https://discussion.fedoraproject.org/t/connecting-my-smartphone-to-my-pc-via-a-hub-causes-filesystem-slowdown/150633/4?u=rokejulianlockhart#:~:text=:speech_balloon:,a%20hub)%20causes%20filesystem%20slowdown.