Hello. I'm definitely not new to KDE or dual-head setups, being KDE/Linux user since 2001.

What I would like to ask about: I have succesfully configured KDE 4 dual-head setup with ATI mobile Radeon on my new laptop, both using Xinerama (opensource driver) and proprietary driver's ATI Bigdesktop. I've chosen to stay with bigdesktop, as Xinerama disables KDE visual effects.

I've configured 2 screens, primary my laptops's 1600x900 panel and secondary my 1920x1080 external monitor. However I'm travelling and not using this setup permanently, so I need Plasma to consider laptop's panel as primary even when not connected to external LCD. And this is what Plasma makes wrong.

When using both screens, all is fine, Kicker panel at bottom of my laptop's screen and external LCD ready as extra workspace (no panels, no applets).

But when I boot without external LCD, while KDM shows correctly on laptop screen, the Kicker panel is missing after login. I've investigated massively and the problem is, that Plasma numbers the screen absolutely wrong and non-logically, i.e. aginst x.org logic.

It numbers external secondary screen as screen=0 and laptop's primary panel as screen=1, and it of course saves panel position using screen=1 value.

However, when there's no external monitor, laptop's screen becomes screen=0 in Plasma's weird system and therefore panel's placed out of visibilty.

Here's that part of plasma-desktop-appletsrc:

[Containments][4]
activity=
desktop=-1
formfactor=2
geometry=0,-46,1600,40
immutability=1
location=4
plugin=panel
screen=1
zvalue=150

Even more weird is the fact, that krandr shows absolutely correct screen setup, laptop's being "Display 1" 0,0 to 1600.900 and external LCD being "Display 2" 1600,1080 to 3520,1080. So only the plasma is all wrong on this.


I tried fresh KDE4 startup (deleted whole .kde in my homedir) but no positive effect. What I need to know how to alter the plasma-desktop-appletsrc to have panel always on laptop's (primary) screen, starting at 0,900 and fillning whole bottom of screen, i.e. ending at 1600,900, whether I'm on one or two monitors.

I hope it's clear what's the problem.

Plasma uses a system called Kephal for this I believe. It is probable that Kephal itself has a bug in this case which breaks this. I would recommend filing a bug report at bugs.kde.org in this case, as Plasma/Kephal should honour the X settings.

Will do, however, I assume there's no workaround to this issue how to modify plasma config file to have:

- KDE correctly handling external screen connected/not connected
- to have Compositing enabled

It's definitely related to plasma, as even KDM handles this correctly and appears always on the correct screen. I'm using debian's stable release, so KDE version is 4.4.5 with some bugfixes backported from higher version by debian team.

Unfortunately I don't think there is a workaround.
You could try editing Kephal's information cache, which is likely either under ~/.local, ~/.config or ~/.kde4