kdm fails to start/restart (but gdm does properly) in kubuntu karmic 64 bits and nvidia driver 185 -- Solved!

[avlas]

Binary package hint: kdm

Most of the times kdm crashes when starting and always when trying to restart. I found a 'workaround' using gdm instead, which does not have the problem at all (that is the reason why I know it is an issue with kdm, at least with nvidia driver 185 and kubuntu karmic 64 bits), but I would prefer not to have to install that many gnome packages to get kde working.

[avlas (avlas)]

I forgot to mention that startx also works.

[Jonathan Thomas (echidnaman)]

X is crashing here, making this a driver issue.

[avlas (avlas)]

Hi Jonathan,
what I cannot understand if it is an issue with the nvidia driver is why then it is only crashing under kdm and never under gdm, isn't it weird? Anyway, if I can do something more to help fixing this bug I will be happy to do it, please let me now.
on the other hand, as I have nvidia driver 185 in my computer, shouldn't it be more appropriate to put nvidia driver 185 than 180?
Thanks for your feedback!

[ChaosEagle (chaosspawn23)]

I have the same problem, it seems happen with nvidia driver 180 and even the latest self-compiled driver. I suspected that it might be upgrade-related, though, as I had kubuntu 9.04 installed earlier (where KDM worked flawlessly with any nvidia driver) and upgraded it through update-manager when karmic was released.
Is there anything I can contribute to help locate the cause of this problem?

[Jonathan Thomas (echidnaman)]

X crashes can only be triggered either by bugs in the driver or X Server itself. KDM just happens to do things differently enough to cause the driver to go down a buggy codepath it contains. There's really nothing we can do from the KDM-side of things.

Unfortunately since the nvidia drivers are closed-source, there's not much we as K/Ubuntu developers can do to help things there. You must throw yourselves to the mercies of the nvidia developers.

[Andreas Jellinghaus (tolonuga)]

same problem here: kubuntu karmic with 2.6.31-15 and nvidia 185 (current packages).
going back to 2.6.31-14 kernel solved the problem for me.

I debugged the issue with strace: kdm doesn't crash, nor does the xserver. the problem
is that X does open("/dev/nvidia0") and that takes about 15 seconds for some reason.
kdm then thinks "starting X server takes too long, something must be wrong" and terminates
the X server (and tries to start a failsafe one).

when you look at the laptop screen (my case: lenovo T61 with nvs 140 quadro chip), the
screen goes black when X is started, and it takes maybe 10 seconds till the nvidia logo
appears. normaly the nvidia logo appears within a few seconds.

in syslog you can see these messages:
Nov 30 15:32:12 yomigaeri kdm[6476]: X server startup timeout, terminating
Nov 30 15:32:15 yomigaeri kdm[6476]: X server died during startup
Nov 30 15:32:15 yomigaeri kdm[6476]: Failed to start X server. Starting failsafe X server.

so you know kdm stopped X server because it took too long to start. in my case X was started
15:31:56, and in strace there was a gap from :57 to :10 or so when open("/dev/nvidia0") was done.

the kernel/dmesg doesn't have any error message from nvidia driver or similar.

[jth (jth)]

Hi
I got the same thing, slow start of X with nvidia causing kdm to abort the start of X.
Blinked screen many times and failed to start X and sometimes I had to try up to ten or more times to get into grapic mode.

I tried different kernels .28 .31-14 .31-15 and nvidia drivers 180 185 and 190 until I found this.

Making the timeout a bit longer in kdm make it work fine.
I found this from Daniel here: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=524751

To resolve the problem change or add in the X-*-Core section in /etc/kde4/kdm/kdmrc
    [X-*-Core]
    ServerTimeout=120

Hope it helps.
--
Johan T
Falun Sweden

[avlas (avlas)]

It worked like a charm!

Thanks a lot, I habe been suffering this annoying behavior for very long time...

[Bruno Bigras (brunoqc)]

Why is it "Fix Committed" for nvidia-graphics-drivers-180 is the change seems to be needed in the kdm package?

Is there an updated package?

[avlas (avlas)]

Sorry, there is not any updated package to fix this issue but the way to solve it by editing /etc/kde4/kdm/kdmrc as jth indicated.

I've changed the bug to new again but I've included solved in the title, I guess it's more appropriate...

[cyril (ivi610)]

it worked for me but for a timeout of 500
By the way, what is the unit of this number?
Moreover, I confirm this affects only kdm but not gdm

[JungleEditor (subscriptions-ruadesign)]

Hi - Thanks for all the info above. Unfortunately jth's fix #10 didn't work for me.

I have the same symptms - KDE starts sucessfully with gdm as the window manager, but not with kdm :

- 'kdm[5107] X server died during startup' 'Failed to start X server. Starting failsafe X server.'
- I can only start the system by a combination of : killall Xorg / killall kdm
  - kdm then respawns and starts correctly
  - Sometimes I have to log-in remotely to issue these commands as my screens are totally blank on ctrl-alt-F1
- I have dual screen monitor and I sometimes I get the message on the bootup monitor 'wrong screen resolution' (think that is in 'safe mode graphics')
- Also in /etc/kde4/kdm/kdmrc I have three similar sections: [X-*-Core] [X-:0-Core] [X-:*-Core], and I adjusted the first one.
- I also tried timeout of 500, but I still cannot start my system normally
- I have a dual-monitor setup, nvidia graphics card GEforce 9300 GE), nvidia driver: 185.18.36

Any help/guideance/ suggestions to try would be most welcome!.

[jth (jth)]

Hi JungleEditor
I would first think that you got another problem since you did not get a timeout problem in the kdm log (syslog in most cases) instead you got "died during startup". Maybe it need a second try or something to initialize or something else differs in the startup.

You could try to use a new 190 driver but I am not sure if this would help if not someone else have fond the cause of your particular problem.
sudo add-apt-repository ppa:nvidia-vdpau/ppa
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys CEC06767
sudo apt-get update
sudo apt-get install nvidia-190-modaliases nvidia-glx-190 nvidia-settings

Also I think it is OK to try even a tenfold longer timeout just to test. I would suggest to find a even more similar or create a new bug report on your issue that include the "died during startup" from kdm . Adding all you relevant syslog, kdm and Xorg logs.
I hope this get you further.

[JungleEditor (subscriptions-ruadesign)]

Hi jth,

Many thanks for your suggestions. I did some further searching and the following Ubuntu forum thread provided a work-around:

http://ubuntuforums.org/showthread.php?t=1343261&page=5
Specificaly doctordruidphd post #47 to disable safe-mode graphics.

Similar discussion here:
https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/491483

Apparently it is a timing/conflict issue and related to gdm/kdm and safe-mode graphics. (so perhaps it is in someway related to this thread too - I'm not sure)

P.S. I have 32bit Ubuntu installed (this thread is for 64 bit) and I have both Gnome and KDE installed