Are you using intel drivers?

please also note your kde/xorg version (alongside the gpu/driver as Christoph has demanded) and whether you're using compositing at all

(In reply to comment #0)
> It looks like I have experienced something very similar 
similar to what?

> I was at the lime listening a radio station stream ...
with what application (browser? is this flash based?)

> then I noticed that my screen was entirely black 
have you been absent meanwhile, ie. did you turn off the screen or dpms power saving (probably) took place?

> with no possibility to do anything 
- has there been a cursor? was it movable?
- could you switch to VT1 or "zapp" (ctrl+alt+backspace, notice that both no more enabled by default in recent Xorg versions, so you should figure if it works anyway)

> from now on ...
nice attempt, but playing that card stopped working like ten years ago - sorry :-(

- I was using compositing along with free diver for ATI 4850 hd grapgic card
- I think it was running on realplay
- normally the screen should turn on when moving the mouse
- no way to go to console mode with Ctrl Alt F1
- no mouse cursor

I have an intel core i5 750, audio is intel

I experienced 3 more freezing :
- one with black screen while listening to a radio station (stream),
- one after the update to 4.4.92 this time with a blue screen like the one of the desktop but without plasmois and this time with no radio on.

This has nothing todo with the fact that I was listening to a radio station on internet but very likeley realated to plasma desktop ; un fortunately this event yields no error message ; this is very nasty because THERE IS NO WAY to regain control of the kde sesion meaning that all data currently being edited is lost making kde unusable.

I experienced 2 more freezing :
- one with black screen while listening to a radio station (stream),
- one after the update to 4.4.92 this time with a blue screen like the one of the desktop but without plasmois and this time with no radio on.

This has nothing todo with the fact that I was listening to a radio station on internet but very likeley realated to plasma desktop ; un fortunately this event yields no error message ; this is very nasty because THERE IS NO WAY to regain control of the kde sesion meaning that all data currently being edited is lost making kde unusable.

you're experienicing either
- a kernel panic (repeating sound, comment #0) 
- or rather an Xorg error (no idea whether the GUI affects real's playback),

probably caused by broken dpms handling and likely related to the ati driver in combination with (opengl?!) compositing or just opengl.

A far guess is that this is caused by a monitor loss and failied re-add.
- call "kcmshell4 kcmkded" and look out for the "Detectiong RANDR" daemon in the lower filed.
- Uncheck and stop that daemon.
- PREPARE for loosing your system with the next step!
- call "xset dpms force off"
-> see whether the problem remains. If not, cross check by re-enabling that daemon and call "xset dpms force off" again to ensure this was causing the trouble.


The fact that you cannot change to a VT (while you used to can) as well as there's no pointer indicates that you cannot leave the "dpms != on" mode (and in consequence X11 doesn't handle even VT change requests, please ensure this (ctrl+alt+f1) works otherwise, but prepare for the failure to return to X (ctrl+alt+f7))

There is also a chance that this is a bug in the input (evdev?) driver. If you've a second machine and an ssh daemon on the broken one, you can try to ssh the broken machine and call

DISPLAY=:0 xset dpms force on

to leave the power saving mode


At least the original report has _nothing_ to do with KDE/KWin but is clearly a driver bug.
to bypass this you can "xset -dpms" to turn this feature off entirely (until the next X start, foce it of via ~/.xprofile, /etc/X11/xorg.conf or an autostart launch - maybe there's even a setting in kde's screensaver settings, dunno)

If "free driver" is supposed to be "fglrx", i suggest to try the radeon driver instead...

The "blue screen" w/o plasmoids sounds like a different issue and needs more detailed description (like whether you see a pointer, can switch VT or suspend compositing) but also sounds like a broken driver (invalid framebuffer) as well.

if this bug is related to the ati driver I shouhd experience the same problem with gnome which is not the case even when using kde apps from this sessiuon !

> if this bug is related to the ati driver I shouhd experience the same problem with gnome
because? ... Gnome is KDE, uses the same gl/x11 calls & abilities, has the same dpms/screensaver settigns and RANDR treating?
sorry but that's a misinformed assumption. the fact that parts of your driver/server may be broken does not imply that all of them are. gnome might have been used as regression test by the ati devs.

a) gnome's desktop afair doesn't use ARGB stuff (reg. not further specified "blue screen" issue)
b) compiz & plugins make different calls to the opengl architecture (in case you're using compiz on gnome at all and not metacity)
c) do you run a screensaver under gnome? does it enter or maybe even /prevent/ dpms?

Now, did you actually try to read comment #7?
-> did you read about and tried on the RANDR daemon? 
-> did you read and try on dpms settings? (to either trigger or prevent the issue)

but, most important and as mentioned:
you lost the ability to switch VTs -> that is an X11 issue. period.
(it works despite running screenlocker/grabbed keys here, just like zapping should)

It looks like this bug has been cured after last releases of som packages bacause I have opened a kde session for more than 2 hours with a radio stream on (firefox) and a screensaver and no crash happened.

Thomas, the last and as nasty bug already reported is the one that I have been experiencing for months :
- after using a lot copy, cut and paste in any apps opened in a kde sesion after a while I experience the following bug :
- total loss of control of any kde window manager features with mouse pointer (still moving) : I mean no way to open the menu of the app, move the app window , close the app, etc and also the same for other apps opened ; the only thing I can do is use keyboard to enter characters in the window where the problem arose or do Ctrl+Alt+Suppr but in this case the window to close the session pops-up with no other way than wait to 30 seconds for a fatal exit choice to be trigged (as mentioned above clicks on any buttons of this window is inactive) ; when exiting all data is lost on all apps opened (real disaster).

Apparently this bug has been reported long time ago by other people as a "classico" ; as I do not collect any error message it is very difficult to bring pertinent information to kde maintainers ; any idea ?

sorry for the delay, working out my drafts ;-)

> the last and as nasty bug already reported

That's an unresolved pointer grab (and not related to this bug, there should however be existing reports)
Either by kwin (?) or one of the clients (popups & combobox dropdowns are best candidates to trigger this)

Unfortunately they're hard to debug as afaik there's no way to query the grabbing client :-(
So you need to determine a reliable context/procedure to trigger it, just in order to be able to determine the culprit.

I recall to got it quite often with konquerors comobox dropdown - but that's quite some time ago (meaning "year/s")

Iff it's in kwin (which iirc only uses passive grabs, though) and you can bring down and focus eg. krunner, you maybe can resolve it by "kwin --replace"

Original bug was (resolved) upstream as suggested in comment #10
ponter grabs/focus stuck have been another bug and not been mentioned for 15 months about after the last comments to this one)

If you still experience pointer grabs in KDE i suggest to file a new bug report against a new KDE version.