Similar bug has started to appear here sometime in November 2011. My system is:
Ubuntu 10.04.3
Linux 2.6.32-37-generic
Dell Optiplex 760

Symptoms:
 * the first occassions were with a blank screensaver + lock. I have returned after an hour to find that the screen is not blanked, it was even updating, but after moving a mouse it went blank and displayed password prompt as it should

 * now a new symptom happens frequently (twice or thrice a week at least), always when I am off the computer for several hours - the X restarts so when I come back, the GDM greeter is on. I have changed the screensaver to space images, might be the reason. Happened even soon after a reboot

# cat /sys/kernel/debug/dri/0/i915_error_state
Time: 1324408252 s 522411 us
EIR: 0x00000000
  PGTBL_ER: 0x00000000
  INSTPM: 0x00000000
  IPEIR: 0x00000000
  IPEHR: 0x01800002
  INSTDONE: 0xffffffff
  ACTHD: 0x03ac4014
  INSTPS: 0x8001e020
  INSTDONE1: 0xbfffffff

# lspci -vvnn

# lspci -vvnn
00:00.0 Host bridge [0600]: Intel Corporation 4 Series Chipset DRAM Controller [8086:2e10] (rev 03)
	Subsystem: Dell Device [1028:027f]
	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
	Capabilities: [e0] Vendor Specific Information <?>
	Kernel driver in use: agpgart-intel
	Kernel modules: intel-agp

00:02.0 VGA compatible controller [0300]: Intel Corporation 4 Series Chipset Integrated Graphics Controller [8086:2e12] (rev 03)
	Subsystem: Dell Device [1028:027f]
	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
	Interrupt: pin A routed to IRQ 33
	Region 0: Memory at fe800000 (64-bit, non-prefetchable) [size=4M]
	Region 2: Memory at d0000000 (64-bit, prefetchable) [size=256M]
	Region 4: I/O ports at ec90 [size=8]
	Capabilities: [90] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable+
		Address: fee0100c  Data: 41c1
	Capabilities: [d0] Power Management version 2
		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Kernel driver in use: i915
	Kernel modules: i915

00:02.1 Display controller [0380]: Intel Corporation 4 Series Chipset Integrated Graphics Controller [8086:2e13] (rev 03)
	Subsystem: Dell Device [1028:027f]
	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
	Region 0: Memory at fe700000 (64-bit, non-prefetchable) [size=1M]
	Capabilities: [d0] Power Management version 2
		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-

00:03.0 Communication controller [0780]: Intel Corporation 4 Series Chipset HECI Controller [8086:2e14] (rev 03)
	Subsystem: Dell Device [1028:027f]
	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
	Interrupt: pin A routed to IRQ 11
	Region 0: Memory at feda6000 (64-bit, non-prefetchable) [size=16]
	Capabilities: [50] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [8c] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
		Address: 0000000000000000  Data: 0000

00:03.2 IDE interface [0101]: Intel Corporation 4 Series Chipset PT IDER Controller [8086:2e16] (rev 03) (prog-if 85 [Master SecO PriO])
	Subsystem: Dell Device [1028:027f]
	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-
	Interrupt: pin C routed to IRQ 18
	Region 0: I/O ports at fe80 [size=8]
	Region 1: I/O ports at fe90 [size=4]
	Region 2: I/O ports at fea0 [size=8]
	Region 3: I/O ports at feb0 [size=4]
	Region 4: I/O ports at fef0 [size=16]
	Capabilities: [c8] Power Management version 3
		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [d0] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
		Address: 0000000000000000  Data: 0000

00:03.3 Serial controller [0700]: Intel Corporation 4 Series Chipset Serial KT Controller [8086:2e17] (rev 03) (prog-if 02)
	Subsystem: Dell Device [1028:027f]
	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
	Interrupt: pin B routed to IRQ 17
	Region 0: I/O ports at ec98 [size=8]
	Region 1: Memory at fe6d8000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: [c8] Power Management version 3
		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [d0] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
		Address: 0000000000000000  Data: 0000
	Kernel driver in use: serial

00:19.0 Ethernet controller [0200]: Intel Corporation 82567LM-3 Gigabit Network Connection [8086:10de] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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
	Interrupt: pin A routed to IRQ 31
	Region 0: Memory at fe6e0000 (32-bit, non-prefetchable) [size=128K]
	Region 1: Memory at fe6d9000 (32-bit, non-prefetchable) [size=4K]
	Region 2: I/O ports at ecc0 [size=32]
	Capabilities: [c8] Power Management version 2
		Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=1 PME-
	Capabilities: [d0] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable+
		Address: 00000000fee0200c  Data: 41d1
	Capabilities: [e0] PCIe advanced features <?>
	Kernel driver in use: e1000e
	Kernel modules: e1000e

00:1a.0 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #4 [8086:3a67] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin A routed to IRQ 16
	Region 4: I/O ports at ff20 [size=32]
	Capabilities: [50] PCIe advanced features <?>
	Kernel driver in use: uhci_hcd

00:1a.1 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #5 [8086:3a68] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin B routed to IRQ 17
	Region 4: I/O ports at ff00 [size=32]
	Capabilities: [50] PCIe advanced features <?>
	Kernel driver in use: uhci_hcd

00:1a.2 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #6 [8086:3a69] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin C routed to IRQ 22
	Region 4: I/O ports at fc00 [size=32]
	Capabilities: [50] PCIe advanced features <?>
	Kernel driver in use: uhci_hcd

00:1a.7 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB2 EHCI Controller #2 [8086:3a6c] (rev 02) (prog-if 20)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin C routed to IRQ 22
	Region 0: Memory at fe6da000 (32-bit, non-prefetchable) [size=1K]
	Capabilities: [50] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME+
	Capabilities: [58] Debug port: BAR=1 offset=00a0
	Capabilities: [98] PCIe advanced features <?>
	Kernel driver in use: ehci_hcd

00:1b.0 Audio device [0403]: Intel Corporation 82801JD/DO (ICH10 Family) HD Audio Controller [8086:3a6e] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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 16
	Region 0: Memory at fe6dc000 (64-bit, non-prefetchable) [size=16K]
	Capabilities: [50] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ Queue=0/0 Enable-
		Address: 0000000000000000  Data: 0000
	Capabilities: [70] Express (v1) Root Complex Integrated Endpoint, MSI 00
		DevCap:	MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
			ExtTag- 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 unknown, Width x0, ASPM unknown, Latency L0 <64ns, L1 <1us
			ClockPM- Suprise- LLActRep- BwNot-
		LnkCtl:	ASPM Disabled; Disabled- Retrain- CommClk-
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed unknown, Width x0, TrErr- Train- SlotClk- DLActive- BWMgmt- ABWMgmt-
	Capabilities: [100] Virtual Channel <?>
	Capabilities: [130] Root Complex Link <?>
	Kernel driver in use: HDA Intel
	Kernel modules: snd-hda-intel

00:1c.0 PCI bridge [0604]: Intel Corporation 82801JD/DO (ICH10 Family) PCI Express Port 1 [8086:3a70] (rev 02)
	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
	Bus: primary=00, secondary=01, subordinate=01, sec-latency=0
	I/O behind bridge: 00001000-00001fff
	Memory behind bridge: fe500000-fe5fffff
	Prefetchable memory behind bridge: 00000000f0000000-00000000f01fffff
	Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
	BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B-
		PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
	Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00
		DevCap:	MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
			ExtTag- 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 #1, Speed 2.5GT/s, Width x1, ASPM L0s, Latency L0 <256ns, L1 <4us
			ClockPM- Suprise- LLActRep+ BwNot-
		LnkCtl:	ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 2.5GT/s, Width x0, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		SltCap:	AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surpise+
			Slot #  5, PowerLimit 10.000000; Interlock- NoCompl+
		SltCtl:	Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
			Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
		SltSta:	Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock-
			Changed: MRL- PresDet- LinkState-
		RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
		RootCap: CRSVisible-
		RootSta: PME ReqID 0000, PMEStatus- PMEPending-
	Capabilities: [80] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable+
		Address: fee0300c  Data: 4181
	Capabilities: [90] Subsystem: Dell Device [1028:027f]
	Capabilities: [a0] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [100] Virtual Channel <?>
	Capabilities: [180] Root Complex Link <?>
	Kernel driver in use: pcieport
	Kernel modules: shpchp

00:1c.1 PCI bridge [0604]: Intel Corporation 82801JD/DO (ICH10 Family) PCI Express Port 2 [8086:3a72] (rev 02)
	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
	Bus: primary=00, secondary=02, subordinate=02, sec-latency=0
	I/O behind bridge: 00002000-00002fff
	Memory behind bridge: fe400000-fe4fffff
	Prefetchable memory behind bridge: 00000000f0200000-00000000f03fffff
	Secondary status: 66MHz- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- <SERR- <PERR-
	BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B-
		PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
	Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00
		DevCap:	MaxPayload 128 bytes, PhantFunc 0, Latency L0s <64ns, L1 <1us
			ExtTag- 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 #2, Speed 2.5GT/s, Width x1, ASPM L0s, Latency L0 <256ns, L1 <4us
			ClockPM- Suprise- LLActRep+ BwNot-
		LnkCtl:	ASPM Disabled; RCB 64 bytes Disabled- Retrain- CommClk+
			ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
		LnkSta:	Speed 2.5GT/s, Width x0, TrErr- Train- SlotClk+ DLActive- BWMgmt- ABWMgmt-
		SltCap:	AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug+ Surpise+
			Slot #  4, PowerLimit 10.000000; Interlock- NoCompl+
		SltCtl:	Enable: AttnBtn- PwrFlt- MRL- PresDet- CmdCplt- HPIrq- LinkChg-
			Control: AttnInd Unknown, PwrInd Unknown, Power- Interlock-
		SltSta:	Status: AttnBtn- PowerFlt- MRL- CmdCplt- PresDet- Interlock-
			Changed: MRL- PresDet- LinkState-
		RootCtl: ErrCorrectable- ErrNon-Fatal- ErrFatal- PMEIntEna- CRSVisible-
		RootCap: CRSVisible-
		RootSta: PME ReqID 0000, PMEStatus- PMEPending-
	Capabilities: [80] Message Signalled Interrupts: Mask- 64bit- Queue=0/0 Enable+
		Address: fee0300c  Data: 4189
	Capabilities: [90] Subsystem: Dell Device [1028:027f]
	Capabilities: [a0] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [100] Virtual Channel <?>
	Capabilities: [180] Root Complex Link <?>
	Kernel driver in use: pcieport
	Kernel modules: shpchp

00:1d.0 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #1 [8086:3a64] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin A routed to IRQ 23
	Region 4: I/O ports at ff80 [size=32]
	Capabilities: [50] PCIe advanced features <?>
	Kernel driver in use: uhci_hcd

00:1d.1 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #2 [8086:3a65] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin B routed to IRQ 17
	Region 4: I/O ports at ff60 [size=32]
	Capabilities: [50] PCIe advanced features <?>
	Kernel driver in use: uhci_hcd

00:1d.2 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB UHCI Controller #3 [8086:3a66] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin C routed to IRQ 18
	Region 4: I/O ports at ff40 [size=32]
	Capabilities: [50] PCIe advanced features <?>
	Kernel driver in use: uhci_hcd

00:1d.7 USB Controller [0c03]: Intel Corporation 82801JD/DO (ICH10 Family) USB2 EHCI Controller #1 [8086:3a6a] (rev 02) (prog-if 20)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin A routed to IRQ 23
	Region 0: Memory at ff980000 (32-bit, non-prefetchable) [size=1K]
	Capabilities: [50] Power Management version 2
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [58] Debug port: BAR=1 offset=00a0
	Capabilities: [98] PCIe advanced features <?>
	Kernel driver in use: ehci_hcd

00:1e.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge [8086:244e] (rev a2) (prog-if 01)
	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
	Bus: primary=00, secondary=03, subordinate=03, sec-latency=32
	Secondary status: 66MHz- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort+ <SERR- <PERR-
	BridgeCtl: Parity- SERR+ NoISA- VGA- MAbort- >Reset- FastB2B-
		PriDiscTmr- SecDiscTmr- DiscTmrStat- DiscTmrSERREn-
	Capabilities: [50] Subsystem: Dell Device [1028:027f]

00:1f.0 ISA bridge [0601]: Intel Corporation 82801JD (ICH10D) LPC Interface Controller [8086:3a1a] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Capabilities: [e0] Vendor Specific Information <?>
	Kernel modules: iTCO_wdt

00:1f.2 SATA controller [0106]: Intel Corporation 82801JD/DO (ICH10 Family) SATA AHCI Controller [8086:3a02] (rev 02) (prog-if 01)
	Subsystem: Dell Device [1028:027f]
	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: 0
	Interrupt: pin C routed to IRQ 32
	Region 0: I/O ports at fe00 [size=8]
	Region 1: I/O ports at fe10 [size=4]
	Region 2: I/O ports at fe20 [size=8]
	Region 3: I/O ports at fe30 [size=4]
	Region 4: I/O ports at fec0 [size=32]
	Region 5: Memory at ff970000 (32-bit, non-prefetchable) [size=2K]
	Capabilities: [80] Message Signalled Interrupts: Mask- 64bit- Queue=0/3 Enable+
		Address: fee0100c  Data: 41b9
	Capabilities: [70] Power Management version 3
		Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot+,D3cold-)
		Status: D0 PME-Enable- DSel=0 DScale=0 PME-
	Capabilities: [a8] SATA HBA <?>
	Capabilities: [b0] PCIe advanced features <?>
	Kernel driver in use: ahci
	Kernel modules: ahci

00:1f.3 SMBus [0c05]: Intel Corporation 82801JD/DO (ICH10 Family) SMBus Controller [8086:3a60] (rev 02)
	Subsystem: Dell Device [1028:027f]
	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-
	Interrupt: pin C routed to IRQ 9
	Region 0: Memory at fe6db000 (64-bit, non-prefetchable) [size=256]
	Region 4: I/O ports at ece0 [size=32]
	Kernel modules: i2c-i801

# cat /var/log/kern.log
...
Dec 20 20:10:52 chihiro kernel: [38661.224009] [drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung
Dec 20 20:10:52 chihiro kernel: [38661.224015] render error detected, EIR: 0x00000000
Dec 20 20:10:52 chihiro kernel: [38661.224025] [drm:i915_do_wait_request] *ERROR* i915_do_wait_request returns -5 (awaiting 3276857 at 3276856)
...

# cat /var/log/Xorg.0.log.old
...
Fatal server error:
Failed to submit batchbuffer: Input/output error
...


Any insight on this bug? It's rather annoying :(