have not had this problem on Karmic, after upgrade to Lucid wit immediate to Maverick - I've got bunch of this
Feb 13 01:04:00 host kernel: [ 763.050594] [drm:radeon_ib_schedule] *ERROR* radeon: couldn't schedule IB(14). Feb 13 01:04:00 host kernel: [ 763.050601] [drm:radeon_cs_ioctl] *ERROR* Faild to schedule IB ! and mess with dual screen use (on Karmic it worked fine) Thinkpad T40 user@host:~$ uname -a Linux doggy 2.6.35-25-generic #44-Ubuntu SMP Fri Jan 21 17:40:48 UTC 2011 i686 GNU/Linux user@host:~$ sudo lspci -vvvv -s 01:00 01:00.0 VGA compatible controller: ATI Technologies Inc Radeon RV250 [Mobility FireGL 9000] (rev 02) (prog-if 00 [VGA controller]) Subsystem: IBM Device 0531 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping+ SERR+ FastB2B+ DisINTx- Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- Latency: 66 (2000ns min), Cache Line Size: 32 bytes Interrupt: pin A routed to IRQ 11 Region 0: Memory at e0000000 (32-bit, prefetchable) [size=128M] Region 1: I/O ports at 3000 [size=256] Region 2: Memory at c0100000 (32-bit, non-prefetchable) [size=64K] [virtual] Expansion ROM at c0120000 [disabled] [size=128K] Capabilities: [58] AGP version 2.0 Status: RQ=48 Iso- ArqSz=0 Cal=0 SBA+ ITACoh- GART64- HTrans- 64bit- FW+ AGP3- Rate=x1,x2,x4 Command: RQ=32 ArqSz=0 Cal=0 SBA+ AGP+ GART64- 64bit- FW- Rate=x4 Capabilities: [50] Power Management version 2 Flags: PMEClk- DSI- D1+ D2+ AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-) Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME- Kernel driver in use: radeon Kernel modules: radeon, radeonfb -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/586243 Title: Xorg freeze: "Failed to schedule IB" Radeon X1200 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs