KDE login fails as root

[comicsans95]

Hello all!
Long-time pclos user but first time with this problem...

Version:  2010.12 KDE

Problem:  cannot login to KDE as root

Root password is accepted, but KDE startup gets a short way (passed the 3rd icon) then logs me out and drops me back to the login splash screen.  If I try a console login, then use "startx", KDE hangs and locks at the same point during startup.

I can log in as guest and get a desktop just fine.

I can switch to root once logged in as guest, but if I log out of guest completely and try to log in as root, I get the same problem.

Problem occurs from LiveCD AND from hard drive install. OK to login as user/guest but not as root.

I have tried multiple downloads and burns of the CD.  (different PCs, CD media, burn rates, etc.) All with same results.  MD5 is good. Media check via livecd is always good.

My one clue to the possible problem:
I have tried this on 8 computers.  5 did not show the problem.  3 did.  All 3 that did use the VIA KM400 chipset with Unichrome graphics.  The others do not. Hard to imagine that is a coincidence.

Not really sure how to diagnose further....

Any suggestions?
Thanks in advance!

[SurferTim]

Hi comicsans95. Did you find a solution to your login challenge? I'm still can't login as root directly on any of my computers with Unichrome graphics. I can login as root if I start a parallel session from a user session, but not by logging out as a user and logging in as root. I guess it is such a small part of the users that it is not a priority. ??

[kjpetrie]

There are two ways to look at this. One is that you ought to be able to log in as root if you really want to. The other is that you should never want to!

It sounds as if there is a hardware/driver conflict during the start-up of KDE with the privileged (ring 0?) code. Can you log in with different desktops or the vesa driver? What do the Xorg logs (in /var/) show?

Then again, while it's an annoying limitation, it shouldn't actually limit you, as you can always open konsole, su to root, and then launch whatever you need to do as root from there.

[SurferTim]

Thanks, but I know about not logging in as root regularly. I login as root to set up software, like Apache, MySQL, FreeRADIUS, firewall, etc. I can login as root in KDE if I start a parallel session. That does for now, but I would like to be able to login as root from the splash screen.

I will try the Gnome desktop and check the log when I get a chance.

ADD: I took a look at the log (very long so I won't post it all), and there seems to be a problem with the driver. This is part of the log that seems to be trying to detect the video resolution, but the major resolutions (like 640x480 and 1024x768) are not supported with this driver. Should I try a different driver?

(II) CHROME(0): Clock range:  20.00 to 230.00 MHz
(II) CHROME(0): ViaValidMode: Validating 768x576 (Clock: 50000)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using mode "768x576" (vrefresh out of range)
(II) CHROME(0): ViaValidMode: Validating 768x576 (Clock: 63070)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using mode "768x576" (vrefresh out of range)
(II) CHROME(0): ViaValidMode: Validating 640x350 (Clock: 31500)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "640x350" (vrefresh out of range)
(II) CHROME(0): Not using default mode "320x175" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 640x400 (Clock: 31500)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "640x400" (vrefresh out of range)
(II) CHROME(0): Not using default mode "320x200" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 720x400 (Clock: 35500)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "720x400" (vrefresh out of range)
(II) CHROME(0): Not using default mode "360x200" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 640x480 (Clock: 25175)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "320x240" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 640x480 (Clock: 31500)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "320x240" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 640x480 (Clock: 31500)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "320x240" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 640x480 (Clock: 36000)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "640x480" (vrefresh out of range)
(II) CHROME(0): Not using default mode "320x240" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 800x600 (Clock: 36000)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "400x300" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 800x600 (Clock: 40000)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "400x300" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 800x600 (Clock: 50000)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "400x300" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 800x600 (Clock: 49500)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "400x300" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 800x600 (Clock: 56300)
(II) CHROME(0): ViaFirstCRTCModeValid
(II) CHROME(0): Not using default mode "800x600" (vrefresh out of range)
(II) CHROME(0): Not using default mode "400x300" (bad mode clock/interlace/doublescan)
(II) CHROME(0): ViaValidMode: Validating 1024x768 (Clock: 44900)
(II) CHROME(0): Not using default mode "1024x768" (interlace mode not supported)

[Texstar]

Switch to VESA mode, login as root. Make sure Desktop Effects are disabled. Switch back to Unichrome and try to login as root. If that doesn't work then I don't know.

[SurferTim]

You did know!! I changed the video driver to xorg-vesa and rebooted. I logged in as root no problem. I am going to leave the vesa setting rather than going back to the Unichrome driver. Do you see any drawbacks to that?

Thanks!!  

UPDATE: I tried going back to the Unichrome driver, and could not login as root again. Then I went to the vesa driver, logged in as root again, changed the driver back to Unichrome driver, but this time I disabled the "3D Hardware Acceleration" under Options, then rebooted. Now I can login as root with the Unichrome driver.

Thanks again!! 

[SurferTim]

I usually don't double-post, but I did a little testing.
The problem is the default setting for the Unichrome driver "3D Hardware Acceleration":
guest is set to "disabled"
root is set to "enabled".

May I suggest the default for root be changed to "disabled" so the LiveCD will work correctly?