[GM45] Compiz does not start when resolution is more than 2048

[Ferrix Hovi]

Binary package hint: xserver-xorg-video-intel

Compiz does not start when the resolution is above 2048 in either direction. This behavior has changed in a recent patch where the area above 2048 would not be drawn correctly (and there is a fix for that too).

Affected version:
xserver-xorg-video-intel 2:2.6.3-0ubuntu9.2

compiz output:
---
Detected PCI ID for VGA:
Checking for texture_from_pixmap: not present.
Trying again with indirect rendering:
Checking for texture_from_pixmap: present.
Checking for non power of two support: present.
Checking for Composite extension: present.
Checking screen 1Comparing resolution (3360x1200) to maximum 3D texture size (2048): Failed.
aborting and using fallback: /usr/bin/metacity

[Ferrix Hovi (ferrix)]

This works for me with the patch 103 re-enabled in mesa. However it appears from bug #146859 and bug #359392 that this patch has side effects for some other chips.

I have re-enabled the patch 103 in the latest package from proposed in my PPA: https://launchpad.net/~ferrix/+archive/ppa

[Martin Olsson (mnemo)]

GM45 uses the same code as the 965 chipset so this is a dupe of 146298.

Let me give you a quick summary of what has happened so far. Note that upstream mesa master for (for 7.5/7.6) has fixed the issue but mesa developers did not cherry pick this fix for the mesa 7.4 stable branch because adding this fix to 7.4 pulls in another commit which in turn unfortunately introduces a breakage for radeon r300 chipsets. We had the >2048 DRI fix for 965/Gx45 cherry picked in ubuntu however but as you point out above it was dropped before release, the reason for the drop is explained here: https://bugs.launchpad.net/ubuntu/+source/mesa/+bug/146298/comments/52

Although, in the end we actually worked around the freeze bug using a hardcoded virtual size so it might be possible to re-activate the 103_bump_965_texture_limit.diff cherry pick. However, please understand that we're dealing with changes that affect _a lot_ of users and our first priority is to ensure that the intel driver does not freeze and only while that objective is met we'll target other potential fixes. The freeze / GPU lockup is a significantly nastier bug than not being able to use compiz on >2048 monitors using 965/GM45 and later cards.

Running the PPA version is probably the best solution for you at this time. Rest assured this issue is well known, please feel free to join #ubuntu-x on FreeNode IRC if you want more information. Thank you.

[Ferrix Hovi (ferrix)]

I know exactly what you are saying but the case is that we have in our hands a fix that does work on several configurations and on others it does not. So in this bug I am suggesting that, if easily done, we could conditionally fix the issue for any sure-shot platforms we have. This is especially important if the fix for one reason or the other is taking more time than expected.