Bugzilla Bug 283331

Until now I tried several version of KDE4, 4.2 from portage in the past, 4.4
from kde-testing recently, and now 4.3 from portage (which is why I post here).
All of them had the hereby described issue on my laptop:

As soon as I open Konsole, opening any kind of menu (main or popup) is a gamble
at best. The same goes for popups like those hints when the mouse stays over a
panel plasmoid. X instantly crashes, restarts and gets me back to kdm. I have a
suspicion that something with font rendering is borked. Sometimes it works, but
mostly it doesn't. At perhaps 30% of sessions, I don't even have to open
Konsole: I log in and as first thing want to quit kpowersave (the KDE3 app). So
I right-click its tray icon to get the menu -> crash.

Opening programs is no problem, all their controls render normally. It's only
the menus and popups that have this issue. Perhaps because they use the same
method to get displayed? I also had it _once_ that when launching Konsole, its
window background stayed visible, but the usual (for me) black text area did
not show up. I see this as another hint that something in Konsole is not right.

I tried disabling desktop effects, but at one time that actually worsened the
problem. I couldn't even open Qt3 menus anymore, the only solution I could
think of was to delete ~/.kde4.

I had nvidia-drivers-180.60 (newest stable) running, but then tried 190.18 in
hope of improvements from NVidia, but to no avail. I did _not_ encounter this
problem with XOrg's nv driver. I am not sure where to start with debugging; I
compiled all kde-base:4 packages with splitdebug, so I can give you debug
information if you tell me where to start.

Reproducible: Sometimes

Steps to Reproduce:
1. Log into kde4 with xserver running on nvidia-drivers
2. Open konsole
3. Open any menu
4. 90% of cases, xserver crashes. If not, then after some more tries.
Actual Results:  
Xorg crashes in almost all attempts to open a menu after Konsole was opened.
There are no apparent messages in ~/.xsession-errors or Xorg.*.log

Expected Results:  
Menus and other popping up items should appear without crashing Xorg :-)

Created an attachment (id=202798) [details]
Some system infos

Created an attachment (id=202799) [details]
xsession-errors

tail of ~/.xsession-errors for a test session:
login, right-click on KPowersave and close it (did not crash).
Then open Konsole, open one of its main menus -> crash.

Created an attachment (id=202801) [details]
Xorg backtrace

Just remerged xorg-server with splitdebug, because I saw a lonely backtrace
message in Xorg.0.log.old last line. Now I get this backtrace from a crash.

I'm a newbie in gentoo, but you can try #revdep-rebuild.
You can also test an another Desktop (fluxbox) to exclude that nvidia-driver
and xorg have an error.

(In reply to comment #4)
> I'm a newbie in gentoo, but you can try #revdep-rebuild.

That was one of the first things I did, of course.

> You can also test an another Desktop (fluxbox) to exclude that nvidia-driver
> and xorg have an error.

I've never had any issues in my years with KDE 3.
Today I got a reply on gentoo.user ML, he said to disable BackingStore in
xorg.conf. Now the crashes seem to have gone fortunately. However, with that I
wouldn't call the bug fixed, but merely circumvented.

And you expect kde team to fix nvidia driver issues?

@wranglers, plz add nvidia maintainers

Sorry for my suggestive tone, of course not. But since it really only happened
with KDE4, I thought maybe they did something wrong. ;-) I've stumbled upon
nvnews.net, where this solution was already mentioned, so I figure NV people
know about this already.

(In reply to comment #7)
> Sorry for my suggestive tone, of course not. But since it really only happened
> with KDE4, I thought maybe they did something wrong. ;-)
Think about it the other way around. Nvidia is the only one having issues.

Read somewhere that setting:
Option "BackingStore" "False"
Under the Device section in xorg.conf

(In reply to comment #9)
> Read somewhere that setting:
> Option "BackingStore" "False"
> Under the Device section in xorg.conf
> 

I wonder what I meant. Too much coffee and over-clickity fingers, probably.
Anyway, nvidia bug. Assigning.

BackingStore doesn't work with nvidia closed drivers for ages now. Enabling
this option will cause crashes. It's know nvidia problem and they recommend
disabling BackingStore. That should solve the problem (assuming you've got it
enabled).

I'm not sure there's anything nvidia maintainers can do about it.

Hmm, how about placing in pkg_postinst some detection code that greps for Xorg
backing store driver option and warning about it? Or just plain postinst
ewarn/elong with no detection.

(In reply to comment #12)
> Hmm, how about placing in pkg_postinst some detection code that greps for Xorg
> backing store driver option and warning about it? Or just plain postinst
> ewarn/elong with no detection.

Maciej,

detection for user configured files doesn't seem the best option to me.
An ewarn/elog should be enough, imho.