2.6.25-rc3 + RS690 + DRM + xf86-video-ati hang

[Jonathan McDowell]

If I enable CONFIG_DRM_RADEON under 2.6.25-rc3 then starting up
X using the xf86-video-ati driver (6.8.0 or latest git) causes the
machine to become unresponsive; while it still pings and will accept
incoming connections they never actually complete and it's not possible
to login over a serial console (the actual video console doesn't display
anything and the monitor reports a loss of sync).

Disabling the kernel DRM option results in X running successfully.
Likewise 2.6.24 works fine with DRM enabled, presumably because the
support for the RS690 was only added in 2.6.25-rc

The last messages from the kernel before it becomes unresponsive are:

[drm] Setting GART location based on new memory map
[drm] Loading R300 Microcode
[drm] writeback test succeeded in 1 usecs

The motherboard in question is an ASUS M2A-VM HDMI, with the analog VGA
output being used. The machine is running an AMD64 with Debian unstable.
I have put the output of lspci, a non drm Xorg.log and a drm Xorg.log
at:

http://the.earth.li/~noodles/xorg-ati-drm/lspci
http://the.earth.li/~noodles/xorg-ati-drm/Xorg.0.log-nodrm
http://the.earth.li/~noodles/xorg-ati-drm/Xorg.0.log-drm

If I can provide any more useful information please let me know.

J.

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