Hello - I'm having couple of problems with KDE's screen saver and power management that I'm hoping someone can give me some suggestions on fixing.

I have a fresh install of KDE (Kubuntu 11.10 x86_64) on an Core i5 system with ATI Radeon HD 5450 (ATI's fglrx binary driver).

I have the screen saver set to lock the screen after 5 minutes and power management setup to suspend the screen after 10 minutes.

I also have several users configured (me, my wife, my kids), and will often use the screen locks "New User" button to switch between them. I've also installed the fast user switcher plasmoid and we use that if we're logged in already.

So my first problem is that often when I come back to this machine and wiggle the mouse to wake the screen, the screen saver unlock dialog is not visible. I see the screen saver, but I get no unlock dialog at all. If I type in my password, it unlocks, so the dialog is there, but not visible. I don't think this is related to the fglrx driver but it's possible - or maybe it's the OpenGL screen savers? I haven't noticed any correlation between the type of screen saver and the dialog being visible or not - I just thought of that now. I'm going to switch to a non-OpenGL screen saver (it was on random before) and see if that makes any difference.

The other problem I'm having is that if after someone switches user, they can start using the other session, but after 10 minutes the screen suspends. I conjecture that the power manager for the first session is still active and has suspended the screen, since it hasn't seen any input. At this point, the screen is totally off and nothing I do can get it to come back - I have to hard reset the machine (I've tried switching VT's but that doesn't work either). So, (assuming that this is the problem) shouldn't the initial sessions power management get disabled when I switch to a different user session? Is there something I need to do to get that to happen?

Anyway, any pointers anyone can give me would be appreciated.

Thanks,
Pete

Screensavers and screen locking are known unfortunately to have problems in keeping the appropriate windows on top, etc. As far as I know, there isn't too much that can be done to solve that issue.

Changes in KDE 4.8 and later involve changing how screen locking works with the assistance of KWin - so it should be more reliable.

KDE Power Management is supposed to detect when the users session is no longer active and disable itself. If you have access to another machine, can you try and access it remotely (using ssh) once the screen has turned itself off?

Then try using various commands such as xset, vbetool and xrandr to try and turn the display back on again. Also, try checking what ConsoleKit believes to be the currently active seat.

FYI,

I was using AMD/ATI's binary fglrx driver and I noticed this in the syslog:

Dec 28 12:22:00 daffy kernel: [496514.436237] [fglrx] ASIC hang happened
... kernel stack dump ...

This seems to be a common problem with this driver and happens when you drive the card with things like OpenGL screen savers.

And when this happens, the whole X server is locked up hard.

Reverting to the open source drivers seems to have fixed my lockup problems.

Thanks.