Bug 19495 - [945GM] Blank screen and (EE) intel(0): overrun on pipe B!
Summary: [945GM] Blank screen and (EE) intel(0): overrun on pipe B!
Alias: None
Product: xorg
Classification: Unclassified
Component: Driver/intel (show other bugs)
Version: 7.3 (2007.09)
Hardware: x86 (IA32) Linux (All)
: medium major
Assignee: Jesse Barnes
QA Contact: Xorg Project Team
Keywords: NEEDINFO
Depends on:
Reported: 2009-01-10 01:44 UTC by Bryce Harrington
Modified: 2009-02-22 22:32 UTC (History)
1 user (show)

See Also:
i915 platform:
i915 features:

intel.Xorg.0.log (35.79 KB, text/x-log)
2009-01-10 01:45 UTC, Bryce Harrington
no flags Details
fix 945 dsparb values (1.75 KB, patch)
2009-01-28 13:03 UTC, Jesse Barnes
no flags Details | Splinter Review

Description Bryce Harrington 2009-01-10 01:44:25 UTC
Forwarding this report from a Ubuntu reporter:

On Ubuntu Intrepid, Fedora Core 9, and OpenSUSE 11.1 Beta 2, all show a blank (black) screen on boot.  For this hardware, the problem is seen on Hardy and Gutsy when using -intel; with -i810 it works properly.  When the issue is seen,  "(EE) intel(0): overrun on pipe B!" is written to the log as well.

(II) Host-to-PCI bridge:
(II) Bus 0: bridge is at (0:0:0), (0,0,9), BCTRL: 0x0008 (VGA_EN is set)
(II) PCI: 00:00:0: chip 8086,27a0 card 10cf,1378 rev 03 class 06,00,00 hdr 00

(--) PCI:*(0:2:0) Intel Corporation Mobile 945GM/GMS, 943/940GML Express Integrated Graphics Controller rev 3, Mem @ 0xf0300000/19, 0xe0000000/28, 0xf0400000/18, I/O @ 0x1800/3
(II) PCI: 00:02:0: chip 8086,27a2 card 10cf,13d8 rev 03 class 03,00,00 hdr 80

[Original Report]
The LiveCD of Intrepid Ibex Beta get a blank (black) screen once it has entered into graphics mode. The same happens with the LiveCD of Hardy and Gutsy.

The computer still works, I can hear the start sound of GDM, and I can log in from GDM, but I just can't see anything on the screen.

With the Feisty's LiveCD the problem does not occur. By viewing the xorg.conf I noticed Feisty uses the i810 driver.

Changing the xorg.conf in Hardy and forcing the use of "i810" driver the problem does not occur. Using the drivers "intel" the problem reoccurs.

In Intrepid Ibex does not work even with the i810 driver.

Notebook: Fujitsu Siemens P1620
VGA: Intel 945GM Express
LCD Native Resolution: 1280x768

lsb_release -rd: Ubuntu 8.04

apt-cache policy xserver-xorg-video-intel:
  Installato: 2:2.2.1-1ubuntu12
  Candidato: 2:2.2.1-1ubuntu12
  Tabella versione:
 *** 2:2.2.1-1ubuntu12 0
        500 http://na.mirror.garr.it hardy/main Packages
        100 /var/lib/dpkg/status
Comment 1 Bryce Harrington 2009-01-10 01:45:03 UTC
Created attachment 21860 [details]
Comment 2 Bryce Harrington 2009-01-10 01:45:51 UTC
it looks like with -intel the xserver is connecting Configured Monitor to VGA output, not to LVDS:

+(II) intel(0): Output VGA using monitor section Configured Monitor
+(II) intel(0): I2C bus "CRTDDC_A" initialized.
+(II) intel(0): Output LVDS has no monitor section
+(II) intel(0): I2C bus "LVDSDDC_C" initialized.
+(II) intel(0): I2C device "LVDSDDC_C:ddc2" registered at address 0xA0.
+(II) intel(0): I2C device "LVDSDDC_C:ddc2" removed.

However later in the log it sees that the VGA out is present but doesn't have anything connected to it.
Comment 3 Jesse Barnes 2009-01-28 13:03:17 UTC
Created attachment 22320 [details] [review]
fix 945 dsparb values

Can you give this patch a try?  We had the wrong DSPARB values on 945 which might have led to underruns.
Comment 4 Michael Fu 2009-02-22 22:32:04 UTC
original bug reporter confirmed his bug is gone in jaunty Jackalope. Close this one, too.

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