No dri (and therefore no compiz) for virtual screen greater than 2048x2048
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Mesa |
Fix Released
|
Wishlist
|
|||
mesa (Ubuntu) |
Fix Released
|
High
|
Unassigned | ||
Jaunty |
Fix Released
|
High
|
Unassigned |
Bug Description
Scenario:
Toshiba L20 laptop, with builtin 1024x768 builtin LCD, Intel i915 graphics card.
External monitor of 1280x1024 resolution
Using the default configuration (after dpkg-reconfigure -phigh xserver-xorg):
mteira@sombra:~$ xrandr -q
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1024 x 1024
VGA disconnected (normal left inverted right)
LVDS connected 1024x768+0+0 (normal left inverted right) 304mm x 228mm
1024x768 60.0*+
800x600 60.3
640x480 59.9
TV disconnected (normal left inverted right)
With this default configuration, the maximum width (1024) is not enough for a multimonitor mode using my two monitors (1024 + 1280), so, I changed my Display Screen subsection to:
SubSection "Display"
After this, I'm able to setup a multimonitor mode using randr, but DRI is no longer available. I'm getting this log:
(EE) intel(0): Cannot support DRI with frame buffer width > 2048.
So, no compiz, no google-earth, no fancy screensavers,...
I've found this thread where it seems that the coordinate registers for the 3D engine are only 11 bits:
http://
BTW, I tested a hacked OSX version on this box some time ago, and it was able to operate Quartz Extreme with both screens at the same time without problems. Probably the screen/display design could be the problem? I find it frustrating, as with a relatively new graphics card I'm not able to use two monitors (with a not that high resolution) and hardware accelerated display at the same time.
[Workaround]
For now, you must not use a Virtual setting larger than 2048x2048 (or 1024x1024 on some chips, or 4096x4096 on some others) if you wish to use compiz. DRI simply isn't supported yet for virtual resolutions greater than that.
Changed in mesa: | |
status: | Unknown → Confirmed |
description: | updated |
Changed in mesa: | |
status: | Confirmed → Fix Released |
Changed in mesa (Ubuntu Jaunty): | |
status: | Fix Released → Confirmed |
Changed in mesa: | |
importance: | Unknown → Wishlist |
Changed in mesa: | |
importance: | Wishlist → Unknown |
Changed in mesa: | |
importance: | Unknown → Wishlist |
As Keith said in the aforementioned post, it is a limitation of the -intel driver and not likely to get fixed upstream.