[Bug 171685] keyboard stops working in kde

[Jesper Goll]

https://bugs.kde.org/show_bug.cgi?id=171685


Jesper Goll <jesper at goll-rossau.dk> changed:

           What    |Removed                     |Added
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                 CC|                            |jesper at goll-rossau.dk




--- Comment #168 from Jesper Goll <jesper goll-rossau dk>  2009-12-11 00:20:36 ---
This looks like one nasty bug. Here is a thing to try out if you are having it
- and if you feel confident about doing repairs from the console command line.
You might need to, in case something goes wrong.

Log in as root. Make a backup copy of your present xorg.conf file. (On my
system it can be found at /etc/X11/xorg.conf.)

Open the original xorg.conf and take a look. It would have several sections in
it that describe input devices. (At least) one of these would be the keyboard.
In my xorg.conf the keyboard section looked like this:

    Section "InputDevice"
      Identifier   "Keyboard[0]"
      Driver       "kbd"
      Option       "XkbLayout" "dk"
      Option       "XkbModel" "microsoftpro"
      Option       "XkbRules" "xfree86"
      Option       "Protocol" "Standard"
      Option       "CoreKeyboard"
    EndSection

If you have the "CoreKeyBoard" option, try commenting it out:

    #  Option       "CoreKeyboard"

and instead put a new "CoreKeyboard" line in the ServerLayout section (unless
it's already there, of course). Your modified ServerLayout section should look 
more or less like this. (Make sure the "Keyboard[0]" specification matches the
one in the section where you out-commented the CoreKeyboard line. It might have
a different number than 0.)

    Section "ServerLayout"
      Identifier   "Layout[all]"
      InputDevice  "Keyboard[0]" "CoreKeyboard"
      InputDevice  "Mouse[1]" "CorePointer"
      InputDevice  "Mouse[2]" "SendCoreEvents"
      Option       "Clone" "off"
      Option       "Xinerama" "off"
      Screen       "Screen[0]"
    EndSection

The new/extra line here is the first input device (the one that mentions
"CoreKeyboard"). Save the modified file, then reboot your machine and see if
this changes your keyboard behaviour. If not, just revert to the original
settings by deleting the modified xorg.conf and renaming your backup copy
"xorg.conf".

Now, why am I suggesting this?

I recently installed KDE 4.3 in a Sun VirtualBox 3.1.0 r55467 (with 1024 MB
RAM, 128 MB graphics memory). The distro I used was the one on the DVD that
came with Linux Format Magazine 126 (the 2009 Christmas edition). With all
current patches installed, it reports the following version numbers:

    openSUSE 11.1 - 2.6.27.39-0.2
    KDE 4.3.2 release 5

After installing Sun's proprietary graphics and input device drivers (aka the
"VirtualBox Guest Additions"), my keyboard went dead. Not intermittently dead,
as in this present bug, but completely and utterly so. The only way to make use
of the keyboard was to get out of the GUI and work in console mode. Rebooting
the machine made no difference; the error simply persisted.

After some heavy experimenting (I shall spare you the details), I found out
that I could revive the keyboard by restoring the backup copy that VirtualBox
had made of my xorg.conf file. It kind of broke my graphics and mouse drivers,
but I could type! I also found that I could (and can) switch the bug on and off
by simply interchanging these settings in xorg.conf. With the "ServerLayout"
approach I have a working keyboard - with the other approach there is nothing I
can do. None of the little Alt-Click/Tab tricks detailed elsewhere in this
thread had any effect in my case.

So isn't this a different bug altogether, then?

It might well be - in which case I apologize for bringing it up - but it might
also be the case that the bug is the same, but that VirtualBox makes it behave
worse than on a regular machine. Whatever is going on appears to be strongly
related to timing issues (fast typing, etc.) - and running KDE in a simulator
obviously changes the timing rules a bit, since the "real" CPU has to take care
of two operating systems instead of just one. (My physical machine is a
ThinkPad Z60m with a single 2 Ghz Centrino processor, running Windows XP.)

The point is, this is so very easy to test: Just find someone who has this bug
and do the mods in xorg.conf (if they are not there already, of course). If
nothing happens, you have ruled out one more potential cause of bug 171685. If
something DOES happen, it ought to be possible to find out why these two core
keyboard settings are not equivalent (as I believe they should be). This again
ought to shed some light on the bug - and you might also be in possession of a
surefire way to reproduce it: Get the Linux Format DVD and install it on
VirtualBox, then set up the Guest Tools...

I realize, of course, that there is about an 80% chance that I am barking up
the wrong tree. If that is so, perhaps this is a good time to close this bug
and start afresh without my misguided comments.

Incidentally, I am writing this on my virtual KDE box and the keyboard has not
failed me even once. When I type quickly enough, though, it does get stuck on
an occasional letter, rrrrrrrrrrrrrrrepeating it for a second or two. I
conclude that the Xorg keyboard does have some issues with timing, but they
seem to behave rather differently depending on how the system is configured.

Sorry about the length of this comment.  :(

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