How to safely downgrade xorg? [matrox G550, mga & Xorg 7.2]

palantir · Last edited by palantir on Mon May 21, 2007 6:06 am; edited 2 times in total

Hi

Today portage decided to pull Xorg 7.2 in, and my Matrox card (G550, using mga driver) suddenly reverted to 1024x768. After hours of trying to fix it, googling, searching forums, etc..., I gave up, and I decided to downgrade to 7.1, which worked perfectly, and wait until some new version comes out.

What I have done is this: I have added to package.mask the following entries, and run "emerge -uaD world". It downgraded, and X now starts and works like it did before.

davidgurvich · Veteran Joined: 23 Apr 2004 Posts: 1063

The advantage of modular Xorg is being able to make incremental changes. Most programs should be fine.

depontius · Advocate Joined: 05 May 2004 Posts: 3509

I got the upgrade to 7.2 earlier this week on 4 systems. My 2 home desktops (nVidia) are just fine. My work desktop (nVidia) downgraded to 800x600, but by putting HorizSync and VertRefresh values into xorg.conf I managed to get 1600x1200 back. My work laptop (ATI, open source 'radeon' driver) also downgraded to 1024x768 when hooked to the same monitor as the desktop. It's got the dual monitor stuff, so putting the same timing fixes in was a little more complex. I still don't have it back to full resolution, but haven't taken the time, since it's not really a necessity for me.

While going back to 7.1 is an option, it would be better to understand and publish how to make 7.2 work correctly.
It would also be good to understand why this has happened, and why it is "better".
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madisonicus · Veteran Joined: 20 Sep 2006 Posts: 1130

palantir · Posted: Thu May 03, 2007 4:08 pm Post subject:

Yes, I really agree with you. Unfortunately, I absolutely had to find a fix as soon as possible, as that computer is used by someone else for work. In the next days however I will probably have to setup gentoo on a twin computer like the one that failed the upgrade, and so I will try to replicate and solve the problem.

What was happening there, was that the resolution was falling back to an absurd 1200x800 (a value which is never mentioned neither in the logs nor xorg.conf, I really don't know where does it come from), while I wanted 1600x1200. The log was complaining about resolutions out of hsync, but I have not been able to find the correct values for it. I will try again, hoping for the best.

I will try, and I will post back here when I have news.

On the other hand, the upgrade on two other computers was very smooth. On a dell running intel's i810 I did not have to touch anything, while on another dell with Ati Radeon x300 I just recompiled the ati-drivers and I had also to explicitly set the resolution (otherwise it shoot up to some 1900xXYX which was just a trifle too high ;-)

palantir · Posted: Fri May 18, 2007 6:21 pm Post subject:

OK, I had time to play with it today, a couple of hours.

I just came to the conclusion that the xorg 7.2 mga drive is broken beyond repair, with respect to the G550 chipset. There is really no such a combination which will give me any reasonable output. With the current monitors I have, what happens is that they either just go to sleep, or they will say that "this video mode is not supported". Further, with some of the parameters X will not be killable, and even if you issue a killall -9 X the monitors will still show the same (bigger is off, smaller works).

Xorg 7.1 is ok.

If someone wants me to post xorg.conf and the logs, I can provide them.