Comment 155 for bug 256142

I have the same issue here on a HP/Compaq D510 SFF computer (business model).
Things worked fine in Ubuntu Hardy but after an upgrade to Intrepid in August, X broke, and is still broken.
I'm running 2.6.27-3 with and xserver-xorg-video-intel 2:2.4.1-1ubuntu4

My display manager is KDM.
Whenever I try to login to KDE4 the screen goes black after the first KDE icon (during startup) appears during KDE initialization.

If I enable desktop effects in Gnome, X also dies.

Restarting X or KDM doesn't help either, I need to reboot the computer.
My Xorg0.log is full of:
  (EE) intel(0): underrun on pipe A!

The last entries in Xorg.0.log before things go crazy are these:
(II) Initializing built-in extension XEVIE
(II) AIGLX: Screen 0 is not DRI2 capable
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is 11, (OK)
drmOpenByBusid: Searching for BusID pci:0000:00:02.0
drmOpenDevice: node name is /dev/dri/card0
drmOpenDevice: open result is 11, (OK)
drmOpenByBusid: drmOpenMinor returns 11
drmOpenByBusid: drmGetBusid reports pci:0000:00:02.0
(II) AIGLX: enabled GLX_MESA_copy_sub_buffer
(II) AIGLX: enabled GLX_SGI_swap_control and GLX_MESA_swap_control
(II) AIGLX: enabled GLX_texture_from_pixmap with driver support
(II) AIGLX: Loaded and initialized /usr/lib/dri/i915_dri.so
(II) GLX: Initialized DRI GL provider for screen 0
(II) intel(0): Setting screen physical size to 338 x 270
(EE) intel(0): underrun on pipe A!
(II) config/hal: Adding input device Microsoft Microsoft 5-Button Mouse with IntelliEye(TM)
(II) LoadModule: "evdev"

(II) Loading /usr/lib/xorg/modules/input//evdev_drv.so
(II) Module evdev: vendor="X.Org Foundation"
        compiled for 1.5.0, module version = 2.0.99
        Module class: X.Org XInput Driver
        ABI class: X.Org XInput driver, version 2.1
(**) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): always reports core events
(**) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): Device: "/dev/input/event3"
(II) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): Found x and y relative axes
(II) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): Found 5 mouse buttons
(II) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): Configuring as mouse
(II) XINPUT: Adding extended input device "Microsoft Microsoft 5-Button Mouse with IntelliEye(TM)" (type: MOUSE)
(**) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): YAxisMapping: buttons 4 and 5
(**) Microsoft Microsoft 5-Button Mouse with IntelliEye(TM): EmulateWheelButton: 4, EmulateWheelInertia: 10, EmulateWheelTimeout: 200
(II) config/hal: Adding input device Apple, Inc Apple Keyboard
(**) Apple, Inc Apple Keyboard: always reports core events
(**) Apple, Inc Apple Keyboard: Device: "/dev/input/event2"
(II) Apple, Inc Apple Keyboard: Found keys
(II) Apple, Inc Apple Keyboard: Configuring as keyboard
(II) XINPUT: Adding extended input device "Apple, Inc Apple Keyboard" (type: KEYBOARD)
(**) Option "xkb_rules" "evdev"
(**) Apple, Inc Apple Keyboard: xkb_rules: "evdev"
(**) Option "xkb_model" "pc105"
(**) Apple, Inc Apple Keyboard: xkb_model: "pc105"
(**) Option "xkb_layout" "se"
(**) Apple, Inc Apple Keyboard: xkb_layout: "se"
(**) Option "xkb_options" "lv3:ralt_switch"
(**) Apple, Inc Apple Keyboard: xkb_options: "lv3:ralt_switch"
(II) config/hal: Adding input device Apple, Inc Apple Keyboard
(**) Apple, Inc Apple Keyboard: always reports core events
(**) Apple, Inc Apple Keyboard: Device: "/dev/input/event1"
(II) Apple, Inc Apple Keyboard: Found keys
(II) Apple, Inc Apple Keyboard: Configuring as keyboard
(II) XINPUT: Adding extended input device "Apple, Inc Apple Keyboard" (type: KEYBOARD)
(**) Option "xkb_rules" "evdev"
(**) Apple, Inc Apple Keyboard: xkb_rules: "evdev"
(**) Option "xkb_model" "pc105"
(**) Apple, Inc Apple Keyboard: xkb_model: "pc105"
(**) Option "xkb_layout" "se"
(**) Apple, Inc Apple Keyboard: xkb_layout: "se"
(**) Option "xkb_options" "lv3:ralt_switch"
(**) Apple, Inc Apple Keyboard: xkb_options: "lv3:ralt_switch"
(II) config/hal: Adding input device Macintosh mouse button emulation
(**) Macintosh mouse button emulation: always reports core events
(**) Macintosh mouse button emulation: Device: "/dev/input/event0"
(II) Macintosh mouse button emulation: Found x and y relative axes
(II) Macintosh mouse button emulation: Found 3 mouse buttons
(II) Macintosh mouse button emulation: Configuring as mouse
(II) XINPUT: Adding extended input device "Macintosh mouse button emulation" (type: MOUSE)
(**) Macintosh mouse button emulation: YAxisMapping: buttons 4 and 5
(**) Macintosh mouse button emulation: EmulateWheelButton: 4, EmulateWheelInertia: 10, EmulateWheelTimeout: 200
(EE) intel(0): underrun on pipe A!
(EE) intel(0): underrun on pipe A!
...

00:00.0 Host bridge [0600]: Intel Corporation 82845G/GL[Brookdale-G]/GE/PE DRAM Controller/Host-Hub Interface [8086:2560] (rev 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
        Region 0: Memory at f8000000 (32-bit, prefetchable) [size=64M]
        Capabilities: [e4] Vendor Specific Information <?>
        Kernel driver in use: agpgart-intel
        Kernel modules: intel-agp

00:02.0 VGA compatible controller [0300]: Intel Corporation 82845G/GL[Brookdale-G]/GE Chipset Integrated Graphics Device [8086:2562] (rev 01)
        Subsystem: Compaq Computer Corporation Device [0e11:00b9]
        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 16
        Region 0: Memory at f0000000 (32-bit, prefetchable) [size=128M]
        Region 1: Memory at fc400000 (32-bit, non-prefetchable) [size=512K]
        Capabilities: [d0] Power Management version 1
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-
        Kernel modules: intelfb