Cannot enable AGP DMA for VIA hardware

Question

As of the current Xorg 7 packages, I can't get AGP DMA working. Here's what Xorg.0.log shows:
[proteus@localhost ~]$ cat /var/log/Xorg.0.log | grep EE
Current Operating System: Linux localhost 2.6.16-ARCH #1 SMP PREEMPT Wed Apr 12 18:59:19 CEST 2006 i686
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(II) Loading extension MIT-SCREEN-SAVER
(EE) VIA(0): Unknown Card-Ids (1565|1200), report this to [email protected] ASAP
(EE) VIA(0): [drm] drmAgpAcquire failed 1023
(EE) VIA(0): [drm] Failed to initialize DMA ring-buffer: 1005
The above is with Openchrome drivers, but the same messages are present with both xf86-video-via and xf86-video-unichrome as well. This really annoys the hell out of me, because a) not having AGP DMA means a very large performance reduction when using OpenGL, and b) AGP DMA worked fine when I was using Xorg 6.8, and with earlier Xorg 7 packages (from when Xorg 7 was in Testing). Could someone please explain to me what is not working, why it's not working, and how to get it working again?

Answer 1

Nope, that doesn't work either.
For what it's worth, I always got the "Unknown Card-Ids" message, even with the Testing version of Xorg 7, and with Xorg 6.8.2 - and AGPDMA works perfectly for both of those.
Now, I tried doing X -configure to create the config file and not getting rid of the vendor/model "information":
VendorName "Unknown Vendor"
BoardName "Unknown Board"
That gets rid of the "failed to initialize ring buffer" error, but AGPDMA is still not enabled:
Current Operating System: Linux localhost 2.6.16-ARCH #1 SMP PREEMPT Wed Apr 12 18:59:19 CEST 2006 i686
(WW) warning, (EE) error, (NI) not implemented, (??) unknown.
(II) Loading extension MIT-SCREEN-SAVER
(EE) VIA(0): Unknown Card-Ids (1565|1200), report this to the driver maintainer ASAP
(EE) VIA(0): [drm] drmAgpAcquire failed 1023
And now, here's something I should have noticed a while ago... Check out these (edited for clarity) screenshots of xorgcfg in textmode:
In Xorg 6.8.x, VIA cards were listed where the red line is pointing. Now they're not listed there, or anywhere in xorgcfg.
Likewise, the "via" driver is simply not listed; again, it was in Xorg 6.8.x, even after the installation of the necessary DRI snapshots for VIA hardware.
Note that the above is observable with any of the available Unichrome drivers installed - xf86-video-via, xf86-video-unichrome, and xf86-video-openchrome all produce the same results.
Also, I can't confirm this for xorgcfg's graphical mode, for the simple reason that the graphical mode just crashes:
[root@localhost ~]# xorgcfg
Warning: Cannot convert string "menu10" to type Pixmap
Warning: Cannot convert string "menu10" to type Pixmap
Can't create rules structure
Think this strange stuff has any bearing on the AGPDMA situation?