drm2 again

[Steve Kargl]

If I compare Xorg.0.log for drm-legacy-kmod to drm-stable-kmod,
the black screen of death seems to be related to this failure in legacy

 (II) RADEON(0): Setting screen physical size to 508 x 285
 failed to add FB for modeset
 (WW) RADEON(0): Failed to set mode on CRTC 0
 (EE) RADEON(0): Failed to enable any CRTC

The only other difference in the Xorg.log file are

legacy contains

 (II) RADEON(0): mem size init: gart size :1fdef000 vram size: s:40000000
 visible:3f7d7000
 (II) RADEON(0): VRAM usage limit set to 928850K

while stable has

 (II) RADEON(0): mem size init: gart size :3fdde000 vram size: s:40000000
 visible:3f4b4000
 (II) RADEON(0): VRAM usage limit set to 925959K

Note, the system does not have an /etc/X11/Xorg.org file.

-- 
Steve