Bug 18821

Summary: [945GM FBC] screen on VGA output disappears after LVDS is turned off
Product: xorg Reporter: Marcin Biernat <boski_cinek>
Component: Driver/intelAssignee: Jesse Barnes <jbarnes>
Status: RESOLVED INVALID QA Contact: Xorg Project Team <xorg-team>
Severity: major    
Priority: medium CC: boski_cinek
Version: unspecifiedKeywords: NEEDINFO
Hardware: x86 (IA32)   
OS: Linux (All)   
Whiteboard:
i915 platform: i915 features:
Attachments:
Description Flags
debug log none

Description Marcin Biernat 2008-11-30 12:17:26 UTC
My hardware:
$ lspci |grep Graphic
00:02.0 VGA compatible controller: Intel Corporation Mobile 945GME Express
Integrated Graphics Controller (rev 03)
00:02.1 Display controller: Intel Corporation Mobile 945GM/GMS/GME, 943/940GML
Express Integrated Graphics Controller (rev 03)

All I have to do is connect my external display (LCD 1440x900, but I guess it's
not important here) and turn off internal LVDS display:

(I'm starting X with LCD connected, because otherwise I can't get native
resolution on my external LCD)

$ xrandr -q
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1600 x 1600
VGA connected 1440x900+0+0 (normal left inverted right x axis y axis) 408mm x
255mm
   1440x900       59.9*+   75.0     59.9*
   1600x1024      60.2
   1400x1050      60.0
   1280x1024      75.0     60.0     60.0
   1280x960       60.0     60.0
   1360x768       59.8
   1152x864       75.0     75.0     75.0     70.0     60.0
   1024x768       75.1     75.0     70.1     60.0     60.0
   832x624        74.6
   800x600        72.2     75.0     60.3     56.2
   640x480        75.0     72.8     75.0     60.0     59.9
   720x400        70.1
LVDS connected 1024x600+0+0 (normal left inverted right x axis y axis) 220mm x
129mm
   1024x600       60.0*+   65.0
   800x600        60.3
   640x480        59.9

$ xrandr --output LVDS --off

And after a while (for now max. 1 or 2 hours) all I see on my external LCD is
one solid color (usually black, which looks like blank screen, but sometimes
white and even other color) on whole screen. Messing with xrandr/restarting X
doesn't help. Only restart bring back to life my external display.

In my /var/log/Xorg.0.log I see lots (hundreds or even thousands) of underrun
on pipe A messages:

$ cat /var/log/Xorg.0.log | grep -e '(EE) intel(0): underrun on pipe A!'|wc -l
26202

$ dpkg-query -l|grep video-intel
ii  xserver-xorg-video-intel                  2:2.4.1-1ubuntu10.1

Work around for this problem is adding line:

Option          "FramebufferCompression"        "false"

to "Device" section in /etc/X11/xorg.conf.
Comment 1 Gordon Jin 2008-12-01 17:52:44 UTC
Please attach Xorg.0.log.
Comment 2 Marcin Biernat 2008-12-02 00:32:42 UTC
Are you sure? As I wrote:
$ cat /var/log/Xorg.0.log | grep -e '(EE) intel(0): underrun on pipe A!'|wc -l
26202
Comment 3 Gordon Jin 2008-12-02 04:58:17 UTC
(In reply to comment #2)
> Are you sure? As I wrote:
> $ cat /var/log/Xorg.0.log | grep -e '(EE) intel(0): underrun on pipe A!'|wc -l
> 26202

You can put only the stuff before underrun error lines. 
And please set option "ModeDebug yes" under device section in xorg.conf.
Comment 4 Jesse Barnes 2008-12-18 14:19:48 UTC
Yeah we need the log; it has other info that can tell us why pipe A is underrunning.  Also, you could try 2.5.x, that has some fixes for underrun problems.
Comment 5 Marcin Biernat 2008-12-28 13:34:50 UTC
Created attachment 21520 [details]
debug log

I finally had time to reproduce this bug in debug mode. I've attached Xorg.0.log.
Comment 6 Jesse Barnes 2009-01-06 13:08:00 UTC
Can you try a more recent release?  2.4.1 is missing several underrun fixes...
Comment 7 Jesse Barnes 2009-01-28 13:00:52 UTC
Ping Marcin, have you been able to try a newer release with some of the fixes for issues like this?
Comment 8 Marcin Biernat 2009-01-28 16:00:42 UTC
bugzilla-daemon@freedesktop.org wrote:
> http://bugs.freedesktop.org/show_bug.cgi?id=18821

> --- Comment #7 from Jesse Barnes <jbarnes@virtuousgeek.org>  2009-01-28 13:00:52 PST ---
> Ping Marcin, have you been able to try a newer release with some of the fixes
> for issues like this?

Hi!
I didn't have opportunity yet to try newer release. I'm on Ubuntu 8.10 
now, but I will try to reproduce this issue on beta version of Jaunty 
(9.04), which probably comes with newer release. Or maybe some of you 
know where I can get newer drivers for 8.04?

Comment 9 Jesse Barnes 2009-01-28 16:31:37 UTC
I think there are some instructions around for building new drivers under 8.04, but otherwise waiting for Jaunty is fine...  You'd have to google around for them though; iirc they were on one of the ubuntu wiki sites.
Comment 10 Michael Fu 2009-02-19 01:28:56 UTC
ping for response, Marcin... 
Comment 11 Marcin Biernat 2009-02-19 03:48:27 UTC
Hi,
I believe the best way to handle this bug is to take a look at proper ubuntu bug report on launchpad:
https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/311895

There are also many others interesting and well documented problems with Intel drivers on launchpad. Just search for "[i945]" phrase. And by the way guys I really believe we have to make those driver best possible, because almost all netbooks are using 945GM, and it looks like netbooks are our chance to get fair market share on "desktops".
Cheers and thanks for all good work,
BeCe
Comment 12 Jesse Barnes 2009-04-10 10:32:01 UTC
Looks like another FIFO related issue, can you try the patch at
https://bugs.freedesktop.org/attachment.cgi?id=24651
Comment 13 Jesse Barnes 2009-06-23 17:04:14 UTC
Timed out on this one; hopefully it's fixed now (either that or it's a dupe of 18491 or 19304 anyway).

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