[regression] [Hardy] virtual desktop parameter crashes X (intel)

[_tom_]

I use a xorg.conf file for dual monitor support (nothing special, just added "Virtual 2560 1024" for xrandr support for two monitors).
After I added this entry to my xorg.conf and tried to log into my gnome session I got a crash (gdm worked fine, but a few moments after the gnome-panel is loaded the xserver crashs).
However when I tried to disable all "additional startup programs" in Session, the gnome-panel loads fine and I don't get a xserver crash. Enabling just any "additional startup program" leads to the crash.

[Sebastien Bacher (seb128)]

Thanks for your comments. This does not appear to be a bug report as such. We appreciate the difficulties you are facing, but it would make more sense to raise your question in the support tracker. http://launchpad.net/support

[_tom_ (tom-gufler)]

Thanks for your answer.
I'm sorry, but I really think this is a grave bug and not a "support" problem. The "Virtual" entry for the xorg.conf file is well documented and necessary for using a dual screen configuration with xrandr (and X alone works without problems with it).
The problem only exists in the above described configuration (kde 4.0 and terminal are working without a problem). I've also created a new test user (so there should not be a problem with a wrong gnome configuration) and the problem persists.

[_tom_ (tom-gufler)]

I can reproduce this error on a second machine.
Affected is only ubuntu Hardy (gnome 2.21.90, xserver 1.4.1~git.., xserver-video-intel-2.2.0.90). The problem doesn't occur with ubuntu Gutsy on the same machine, so this is a REGRESSION and therefore this bug should be reopened.

[_tom_ (tom-gufler)]

After further research I discovered, that "Virtual" values bigger than 2048 cause this problem. As stated before only Hardy is affected, values bigger than 2048 are working fine in Gutsy.

[Sebastien Bacher (seb128)]

looks like an xorg issue

[unggnu (unggnu)]

I can confirm this under Hardy with a little difference. For me X crashes while gdm is starting but at least there is a working X server for some seconds and it only happens if I add the line "Virtual 3046 1050" to xorg.conf which works fine in Gutsy. DRI works until Virtual of 2048 2048 on Intel chipset so there should be no problem since it is smaller.

[unggnu (unggnu)]

I guess it is an Intel driver bug.

[unggnu (unggnu)]

DRI is only possible if each size is 2048 or lower so direct rendering is not possible for my resolution (Bug #146859) but it still works in Gutsy without DRI.
I have found a way to let it in Hardy work.
To make X and rendering with Exa faster I have added these lines
        Option "AccelMethod" "EXA"
        Option "ExaNoComposite" "false"
        Option "MigrationHeuristic" "greedy"
to my xorg.conf. With them X starts fine with my Virtual size of "3046 1050".
Without them my window manager crashes after some seconds after start. At least I see a mouse and can move it.

[unggnu (unggnu)]

This particular bug has already been reported and is a duplicate of bug #188178, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can add, or to see if there is a workaround for the bug.
Feel free to continue to report any other bugs you may find.