So I installed KDE 4.6.1 on Exherbo Linux using systemd as init system, and basically everything seems to work fine. But: When I log out, the screen just goes black and shows the normal X cursor. I can move the cursor, and on certain areas it changes from arrow to text bar. When I enter my password where I think the password field should be, the cursor changes to the KDE themed one, but the screen remains black. When I ssh to the machine and restart the KDM service manually, everything works again.

I looked into kdm.log, ~/.xsession-errors and daemon.log, all I get is a bunch of messages about failed dbus connection (the same ones everyone seems to be getting), and something about default face not found. I tried copying an image as default face but that didn't help. Deleting /var/tmp/kdecache-USER also seems to do nothing.

Very unusual. This is most likely to an X related driver issue unfortunately. If you logout with Compositing disabled, does everything work fine?

I'll try that, but I can only do it on Monday, as that's my work PC we're talking of. In the meantime, are there any logs I could post that might help pinpoint the problem?

Examining the content of /var/log/Xorg.0.log might help. Checking /var/log/messages probably wouldn't go amiss either...

Disabling compositing via kwinrc indeed fixed the problem, thanks a lot. This is the video card I'm using:

Code: Select all

# lspci -vv
01:00.0 VGA compatible controller: ATI Technologies Inc RV710 [Radeon HD 4550] (prog-if 00 [VGA controller])
        Subsystem: Dell Device 0002
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
        Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
        Latency: 0, Cache Line Size: 64 bytes
        Interrupt: pin A routed to IRQ 48
        Region 0: Memory at e0000000 (64-bit, prefetchable) [size=256M]
        Region 2: Memory at f7df0000 (64-bit, non-prefetchable) [size=64K]
        Region 4: I/O ports at dc00 [size=256]
        Expansion ROM at f7e00000 [disabled] [size=128K]
        Capabilities: [50] Power Management version 3
                Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
        Capabilities: [58] Express (v2) Legacy Endpoint, MSI 00
                DevCap: MaxPayload 128 bytes, PhantFunc 0, Latency L0s <4us, L1 unlimited
                        ExtTag+ AttnBtn- AttnInd- PwrInd- RBE+ FLReset-
                DevCtl: Report errors: Correctable- Non-Fatal+ Fatal+ Unsupported-
                        RlxdOrd+ ExtTag- PhantFunc- AuxPwr- NoSnoop+
                        MaxPayload 128 bytes, MaxReadReq 128 bytes
                DevSta: CorrErr- UncorrErr- FatalErr- UnsuppReq- AuxPwr- TransPend-
                LnkCap: Port #0, Speed 2.5GT/s, Width x16, ASPM L0s L1, Latency L0 <64ns, L1 <1us
                        ClockPM- Surprise- LLActRep- BwNot-
                LnkCtl: ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
                        ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
                LnkSta: Speed 2.5GT/s, Width x16, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
                DevCap2: Completion Timeout: Not Supported, TimeoutDis-
                DevCtl2: Completion Timeout: 50us to 50ms, TimeoutDis-
                LnkCtl2: Target Link Speed: 2.5GT/s, EnterCompliance- SpeedDis-, Selectable De-emphasis: -6dB
                         Transmit Margin: Normal Operating Range, EnterModifiedCompliance- ComplianceSOS-
                         Compliance De-emphasis: -6dB
                LnkSta2: Current De-emphasis Level: -6dB
        Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
                Address: 00000000feeff00c  Data: 4199
        Capabilities: [100 v1] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
        Kernel driver in use: radeon
        Kernel modules: radeon


As you can see, it's the in-kernel radeon driver, kernel version 2.6.38 with the firmware blobs R600_rlc.bin and $700_rlc.bin compiled into the kernel, those were downloaded from http://people.freedesktop.org/~agd5f/radeon_ucode/

Not much that can be done unfortunately... you may be able to disable certain Desktop Effects which are causing this (trial and error will be your friend here). Otherwise, updating the driver is your only option.