Comment 3 for bug 800226

Created attachment 48233
drm.debug=0x0e dmesg from failed boot

-- CPU: Intel Core(TM) i3-2100 CPU @ 3.10GHz (Sandy Bridge)
-- GPU: Intel Corporation Sandy Bridge Integrated Graphics Controller [8086:0102] (rev 09) (prog-if 00 [VGA controller])
-- system architecture: 32-bit
-- Linux distribution: Ubuntu 10.10 and 11.04
-- Package versions:
   libdrm - 2.4.21-1ubuntu2 and 2.4.23-1ubuntu6
   xf86-video-intel - 2:2.12.0-1ubuntu5.2 and 2:2.14.0-4ubuntu7
   kernel - 2.6.35-24.42-generic (2.6.35.8) through 2.6.39.1

This system is a desktop one with a eDP->LVDS converter (CH7511B) for the all-in-one panel and it only works with VESA. As soon as KMS kicks in it goes black and doesn't come back. External monitors still work fine, its just the internal panel that is black. Ubuntu maverick and natty were tested, as well as a 2.6.39.1 kernel. the 2.6.39.1 kernel actually hung with an external monitor, with additional messages like these at the end

PCH HDCP audio interrupt

Followed by a two additional DRM messages:

<7> [ 17.668935 ] [drm.ironlake_dp_detect], DPCD: 0000
<7> [ 245.874118] [drm:i915_hotplug_work_func], running encoder hotplug functions