[i845g] Blank screen problem on login, logout, power savings mode, tty switch etc

[Dan Munckton]

Binary package hint: xorg

Setup:

Dell Inspiron 1100 Laptop
Card: Intel 845G
Driver: intel / i915
OS: Fresh install of Lucid 10.04

Screen goes blank most (but not all) of the time when logging in just after gdm clears the screen (it never comes back). Also switching user, or when swapping to a virtual terminal. 90% of the time I found I can make the display come back by logging in via SSH and running:

  sudo vbetool dpms on

If I can get to desktop, but leave the computer untouched for long enough for power saving to kick in, X drops to a blank screen and then seems to get itself into some sort of crazy loop ...

  1) Blank screen
  2) VT with last 2 syslog entries
  3) Black screen with a panel of vertical black and white lines top center
  4) Loop

This cycle can be broken by shutting down the gdm service. Noticeable messages in the Xorg logs when this is happening are:

  "Failed to submit batchbuffer: Input/output error"

And there are details of an error in /sys/kernel/debug/dri/0/i915-error-state (which I will upload later).

Creating an /etc/X11/xorg.conf with the following contents ...

  Section "ServerFlags"
   Option "BlankTime" "0"
   Option "StandbyTime" "0"
   Option "SuspendTime" "0"
   Option "OffTime" "0"
  EndSection

Seems to have stopped this second problem occurring, although I need to test for longer to be certain. Simply disabling power saving in System > Power Management didn't seem to stop it happening.

UPDATE: actually the above modifications to xorg.conf don't seem to have worked, it still goes into the crazy loop when left for a short while.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: xorg 1:7.5+5ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-21.32-generic 2.6.32.11+drm33.2
Uname: Linux 2.6.32-21-generic i686
Architecture: i386
Date: Sun May 9 20:09:26 2010
DkmsStatus: Error: [Errno 2] No such file or directory
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100427.1)
Lsusb:
 Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 003 Device 002: ID 045e:0040 Microsoft Corp. Wheel Mouse Optical
 Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: Dell Computer Corporation Inspiron 1100
PccardctlIdent:
 Socket 0:
   no product info available
PccardctlStatus:
 Socket 0:
   3.3V 32-bit PC Card
ProcCmdLine: BOOT_IMAGE=/boot/vmlinuz-2.6.32-21-generic root=UUID=2ccf041c-c76d-4ea4-94f8-f26ba8957e31 ro quiet splash
ProcEnviron:
 LANG=en_GB.utf8
 SHELL=/bin/bash
SourcePackage: xorg
Symptom: display
dmi.bios.date: 10/18/2004
dmi.bios.vendor: Dell Computer Corporation
dmi.bios.version: A32
dmi.board.name: 09U784
dmi.board.vendor: Dell Computer Corporation
dmi.chassis.type: 8
dmi.chassis.vendor: Dell Computer Corporation
dmi.modalias: dmi:bvnDellComputerCorporation:bvrA32:bd10/18/2004:svnDellComputerCorporation:pnInspiron1100:pvr:rvnDellComputerCorporation:rn09U784:rvr:cvnDellComputerCorporation:ct8:cvr:
dmi.product.name: Inspiron 1100
dmi.sys.vendor: Dell Computer Corporation
system:
 distro: Ubuntu
 codename: lucid
 architecture: i686
 kernel: 2.6.32-21-generic
xkbcomp:
 Error: command ['xkbcomp', ':0', '-w0', '-'] failed with exit code 1: No protocol specified
 Error: Cannot open display ":0"
                   Exiting

[Dan Munckton (munckfish)]

Contents of /sys/kernel/debug/dri/0/i915-error-state when it goes into the crazy loop:

Time: 1273429354 s 908086 us
EIR: 0x00000000
  PGTBL_ER: 0x00000000
  INSTPM: 0x00000000
  IPEIR: 0x00000000
  IPEHR: 0x18000001
  INSTDONE: 0x01ffffc1
  ACTHD: 0x003db000

Related Xorg.0.log attached too.

[Rob Glenn (glennra)]

I also have these symptoms on my Inspiron 1100.

When comparing X logs from a successful boot and one that came up blank, I noticed the following difference:

< (II) intel(0): Output VGA connected
---
> (II) intel(0): Output VGA disconnected

Note that nothing was connected to the VGA output in either case. (anybody know how to configure X so that it ignores the external monitor connector?)

As an experiment, another time it came up blank I tried connecting an external monitor and the login screen appeared on the external monitor and I was able to log in! However, there were still problems such as no mouse pointer.

I also discovered that it is possible to (eventually) get a virtual console on the laptop display by randomly banging on ctrl-alt-(F1-F6) until one appears.

None of this has anything to do with the looping/vertical lines problem. I still observe that as reported in the bug.