fonts corrupts after a while

[Jacob Emcken]

After using the system for a short while fonts starts corrupting on screen.
I've reproduced this both with "Desktop Effects" enabled and disabled.

I'm not sure if this is actually trigged by the amount of applications open... its really hard to tell what actually triggers it.

As soon as I "Change Desktop background" -> "Fonts" -> "Details..." and change DPI its like the screen refreshes for looks alright for a while.

This is my graphic card (from lspci):
    00:02.0 VGA compatible controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)

I've added the following to the xorg.conf inorder to get my external screen to work:
                Virtual 1680 1050

I'm using Jaunty:
    Description: Ubuntu jaunty (development branch)
    Release: 9.04

I've attached some screenshots of the problem.

[Øyvind Stegard (oyvindstegard)]

I'm seeing something similar. Certian characters get corrupted and stay that way. It's very persistent and a redraw does not fix it. Also happens without Compiz.

Font settings:
- Subpixel AA (RGB)
- 96 dpi
- Medium hinting
- Other font-settings at defaults

ATI X1400 Radeon Mobile (using radeon-driver with EXA), 1680x1050 screen resolution
Ubuntu Jaunty beta

I'm attaching an image which shows the problem.

[Øyvind Stegard (oyvindstegard)]

And then the title of this bug report got corrupted :)

[Øyvind Stegard (oyvindstegard)]

Once a certain glyph has been corrupted, it's like I said very persistent (like it's been cached somewhere).

[Øyvind Stegard (oyvindstegard)]

I haven't been able to reproduce this problem when using XAA-acceleration in the radeon driver. So it might be related to EXA and graphics driver (there are other corruption bugs with this).

[jerrylamos (jerrylamos)]

Font corruption on jaunty on IBM Thinkpad R31 i830 video graphics. Intrepid has no such problem.

Attached is a screenshot showing defective characters running at the moment "AccelMethod" "uxa" on .

Linux version 2.6.30-020630rc4-generic (root@zinc) (gcc version 4.2.3 (Ubuntu 4.2.3-2ubuntu7)) #020630rc4 SMP Fri May 1 09:06:03 UTC 2009

VGA compatible controller: Intel Corporation 82830 CGC [Chipset Graphics Controller] (rev 04)

I've tried various System Preference Appearance Font selections however they all fail.

Problem first started showing up on some updates before jaunty beta and has been there ever since. I tried narrowing it down. I'm not sure, but I expect it showed up about the time it was no longer necessary to do "NoAccel" on i830 and i845 Intel video graphics.

After a few minutes things get unreadable and I dual boot back to Intrepid.

It's a 1 gHz laptop which is quite usable on ubuntu for most purposes except jerky internet video.

At this point in this entry "d" and "N" "J" "f" are just big black blotches.

Jerry

[Denis_AeC (denis.romand-aliceadsl)]

Hello !
Same problem on my PC with ATI Radeon 9200 SE RV280. It happened as soon as I have been able to activate "normal" visual effects (bug : https://bugs.launchpad.net/bugs/368219). When I go back to "no" visual effects (+ reboot), the problem does not occur as long as I don't activate again "normal" effects.
Once it begins to happen, it seems to affect the display of one or more font characters and all occurence of these characters are corrupted. It's sometimes refreshed when changing display from an application to another, but not always.

[Denis_AeC (denis.romand-aliceadsl)]

Another screen copy form the top of this page in Firefox !

Regards

Denis

[Bryce Harrington (bryce)]

Hi jacob-emcken,

Thanks for including an image to demonstrate the issue. Could you also please attach the output of `lspci -vvnn`, and attach your /var/log/Xorg.0.log or Xorg.0.log.old file from after reproducing this issue. If you've made any customizations to your /etc/X11/xorg.conf please attach that as well.

[This is an automated message. Apologies if it has reached you inappropriately; please just reply to this message indicating so.]

[Etienne Goyer (etienne-goyer-outlands)]

Bryce,

Attached Xorg.0.log and output of lspci. My laptop shows this behavior 100% of the time. I am with you here at the UDS; if you want my laptop to bang at it, it's yours.

Thanks a bunch.

[Øyvind Stegard (oyvindstegard)]

I've found that using only gray-scale anti-aliasing helps a lot on this problem. Only rarely do fonts get corrupted when using gray-scale AA, at least with my ATI X1400+radeon-driver+EXA. If I switch to sub-pixel AA (Jaunty default), it will happen a lot faster and the problem gets annoying.

[Etienne Goyer (etienne-goyer-outlands)]

Disabling acceleration (Option "NoAccel" "true", in the Device section of xorg.conf) fixed it for me. I do not appear to have the font corruption problem anymore. I am using the intel driver with an Intel 82830 CGC.

[Tall Paul (paul-mtnlist)]

I am having the same problem on a Gateway Solo 1450.

While researching this problem, I think I have found that the developers of the Intel driver have found a problem with the driver and fixed it. I have no idea when it will be available for an easy install on Ubuntu.

I wish I could link to the bugtracking on this... I apologize.. I didn't bookmark it!

[Geir Ove Myhr (gomyhr)]

It seems that this happens over a range of video cards (Radeon, i855, i830 from what I've seen here). That probably means it is not a driver issue. Would anyone care to test with Karmic, to see if it is fixed there? (daily live available from http://cdimage.ubuntu.com/daily-live/ , alpha-2 should soon be at http://cdimage.ubuntu.com/releases/9.10/ ).

If it is still a problem, it would be nice if somebody could compile a list of affected video cards.

[mob (mcartman)]

same problem on an acer travelmate 220

[metellius (haraldhv)]

For intel users experiencing this, this is probably fixed by a bug in drm-intel in the linux kernel, and was fixed with 2.6.30-rc5 (2.6.30 is now released). For me upgrading the kernel fixed this problem.

For reference, see the second paragraph here:
http://anholt.livejournal.com/41132.html

[Declan Logue (dloguebumf)]

I've got the same problem on an old Dell Latitude C400. I see that metellius seems to have cracked this problem - how would I go about updating the kernel (and you can safely assume a low level of technical skills on my part - sorry I only installed Ubuntu a few days ago). Thanks in advance

[Bryce Harrington (bryce)]

Since we have the 2.6.31 kernel in Karmic, this should now be fixed in karmic.

[errans (pytheaserrans-deactivatedaccount)]

I have this problem on my thinkpad x30--
00:02.0 VGA compatible controller [0300]: Intel Corporation 82830 CGC [Chipset Graphics Controller] [8086:3577] (rev 04)
00:02.1 Display controller [0380]: Intel Corporation 82830 CGC [Chipset Graphics Controller] [8086:3577]

The same font corruption and lines of text randomly disappear. There are other rendering bugs also.

I have tried upgrading to kernel 2.6.30 and 2.6.31-rc3 from ~kernel-ppa to no avail. Unless there is some other change in Karmic, perhaps to the X server, which might fix the problem it does not appear as if this is the fix.
I am seeing this in KDE and saw it in compiz, but compiz no longer loads. Acceleration is set to uxa and tiling is set to off in xorg.conf which seems to help slightly.