Hi list,

Two days ago, I upgraded from F22 to F24. The dnf upgrade succeeded and applications seem to work, but there's a new, serious desktop usability problem:

I'm using a dual-screen setup (LVDS + external monitor), where I usually set Primary dIsplay = external monitor. Moreover, I place the KDE Panel also on the external monitor. When I do that and try to navigate through the Application Menu (launcher with cascading popup menus) or when I click / move over a desktop widget, the following happens:

- After a mouse left click on the KDE menu icon (left hand side of KDE Panel), the menu pops up only after a delay of >= 1 second
- When the mouse pointer is moved to another item in a popup menu, the focus visibly jumps from item to item, and a delay of at least 1 second is added on every intermediate item.
- When I click / move over a desktop widget, the desktop reacts with a delay of >= 1 second

The delay problem consistently disappears when I set Primary display = Laptop Screen, even though the KDE Panel remains on the external monitor. It's strange that the KDE Panel does not move to the Primary display -- I'm likely seeing the following bug

https://bugzilla.redhat.com/show_bug.cgi?id=1322724
Bug 1322724 - Plasma panel not on primary screen

in F24 as well.

Also, the delay problem typically reappears when I go back to Primary dIsplay = external monitor. Only in two out of perhaps a dozen logout-login cycles, I observed that the delay problem was gone, despite the fact that I had Primary dIsplay = external monitor. This may indicate some kind of race condition.

Since this was an upgrade, I also tried the following, but the delay problem behaved the same:
- Remove the contents of ~/.cache
- Temporarily remove ~/.config, ~/.local and ~/.kde and login to KDE
- Login to KDE as another user

Version-release numbers:


Any idea which component should be blamed or how to debug this problem?

I wish some KDE debug messages could be seen in ~/.xsession-errors (I enabled the debug messages using kdebugsettings), but I don't see any of the familiar messages - maybe something is broken with the KDE debug messages as well.


Thanks

Fredy Neeser
IBM Zurich Research Laboratory
CH-8803 Rueschlikon, Switzerland