Bug 14066 - [845] -intel produces corrupt display on older chipsets (i845G)
Summary: [845] -intel produces corrupt display on older chipsets (i845G)
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: Hong Liu
QA Contact: Xorg Project Team
URL: https://bugs.launchpad.net/ubuntu/+so...
Keywords: NEEDINFO
Depends on:
Reported: 2008-01-13 21:35 UTC by Bryce Harrington
Modified: 2008-02-18 19:22 UTC (History)
2 users (show)

See Also:
i915 platform:
i915 features:

validate max clock for probed mode (903 bytes, patch)
2008-01-27 19:02 UTC, Hong Liu
no flags Details | Splinter Review

Description Bryce Harrington 2008-01-13 21:35:07 UTC
Older Intel chipsets are not well supported by -intel.  In the case of i830M
and i845 as examples, X starts but has a corrupt display.  This is preventing
Ubuntu from being able to fully deprecate the -i810 driver, because while these
chipsets are old, they're still in use by many users we wish to support.

Original bug report:

== i845G ==
"I too have a Fujitsu Scenic with integrated Intel graphics, and I have a
similar problem with the release version of 7.10. It was a clean install of the
OS, not an upgrade or dual boot.

The symptoms are; From power up, the Ubuntu splash screen and progress bar are
displayed ok. Once the progress bar reaches the end and the splash screen
closes, there is a brief delay then the display corrupts with vertical green,
white, blue and black lines. The circular mouse cursor with the rotating dots
is also displayed but the dots and cursor freeze. The display then flashes once
to black then the vertical lines are displayed again, in a different pattern.
The PC freezes at this point and I have to power off to restart it.

I can get round this by tapping the F8 key several times as soon as the splash
screen closes, and the PC boots normally. I don't know if the F8 key does
anything specific or if any F key could be used.

I also think that if you reboot the PC, it restarts as normal. It is only when
you power up from cold that this happens, but I haven't confirmed this yet."

Xorg.0.log:  http://launchpadlibrarian.net/10170344/Xorg.0.log
xorg.conf:   http://launchpadlibrarian.net/10170348/xorg.conf
Photo:       http://launchpadlibrarian.net/10183891/DSCF0110.JPG
Comment 1 Wang Zhenyu 2008-01-21 23:11:52 UTC
Can you try with current git tip version? That we originally ignore i830M and 845G pci ids, so some code paths might slip.
Comment 2 Hong Liu 2008-01-27 19:02:15 UTC
Created attachment 13980 [details] [review]
validate max clock for probed mode

From the log, the EDID doesn't set the prefer bit for its detailed mode.
So we doesn't choose:
(II) intel(0): Modeline "1024x768"x75.1   78.80  1024 1040 1136 1312  768 769 772 800 +hsync +vsync (60.1 kHz)

But the EDID claims support VESA standard 1024x768@75Hz mode:
(II) intel(0): Modeline "1024x768"x74.9   82.00  1024 1088 1192 1360  768 771 775 805 -hsync +vsync (60.3 kHz)

Which exceeds the maxclock (80Mhz) of this monitor.

Please try the attached patch.

Comment 3 Hong Liu 2008-01-27 19:03:07 UTC
The patch is against X server.
Comment 4 Michael Fu 2008-02-02 23:53:15 UTC
Bryce, would you please add the bug repoter to the cc field and introduce him to comment on this bug? thanks.
Comment 5 Bryce Harrington 2008-02-03 01:26:33 UTC
I attempted to add the original reporter's email address to the CC but Bugzilla returned the following error:

"Bugzilla was unable to make any match at all for one or more of the names and/or email addresses you entered on the previous page.
Please go back and try other names or email addresses.
stephen.pountney@tiscali.co.uk did not match anything "
Comment 6 Bryce Harrington 2008-02-03 01:27:53 UTC
I've responded to the Launchpad bug encouraging the reporter to join discussion here.
Comment 7 John Dorfman 2008-02-03 09:55:01 UTC

I have the i830 chipset on my laptop.  With Xorg-server version, I was getting visual corruption in Xorg.  If I would restart Xorg, I would get a black screen with only the mouse pointer visible.  Lastly, if I resumed with Tuxonice, the insides of windows would not render.

Anyway, when I manually patched xorg-server with the patch that was attached by Hong Liu, my problems appear to be solved!  All the above conditions appear to be fixed...

If you need any additional info from me to confirm this, please let me know.

Comment 8 John Dorfman 2008-02-03 10:10:10 UTC
okay, I do still sometimes get a little corruption at the top of the screen (for top 3 or 4 rows of pixels evenly spaced whitish rectangles appear).  it only seems limited to that area which is better than it was before as corruption could appear anywhere on the screen.  if i switch desktops and go back, the corruption is gone.

my other problems mentioned in the previous post though are fixed.  guess i will reopen this as it is not totally fixed. 

so in summary, much better, but not quite fixed.
Comment 9 John Dorfman 2008-02-03 10:25:05 UTC
sigh, okay, I am also still seeing some corruption on other parts of the screen.  it appears to be a dark 3 or 4 pixel band that goes across the screen.  it is about an 1/8th up from the bottom of the screen and usually goes away when I switch to another desktop and back.
Comment 10 Michael Fu 2008-02-03 16:18:53 UTC
John, please pay attention to the bug title. this bug is for 845. bug# 14065 is the one for 830 chipset. We specifically asked Bryce opened two bugs for 845 and 830 platform each.

would you please add your finding to bug# 14065?

Still need bug reporters' comment on 845, or we have to reject this bug.
Comment 11 John Dorfman 2008-02-03 16:41:44 UTC
oops, sorry about that.  okay, reposted the previous comments i made on bug 14045.
Comment 12 Hong Liu 2008-02-18 19:22:35 UTC
patch is commited to X server (with commit id d3c36fe721edc55636438bc3e0e7a6c03f62784e 4b5b6e7baab58072a983d2ec136965f404c3a74a).
I am closing this bug since there is no response from original reporter.

Please repoen it if problem still exists.


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