Comment 9 for bug 1070978

Created attachment 69076
dmesg after reproducing it with drm.debug=0xe

This commit causes a lenovo v490u to have a black screen after booting

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=4344b813f105a19f793f1fd93ad775b784648b95

It's working properly in 3.7, but 3.6 is broken without reverting that, and that commit was backported to the stable kernels which are now broken also. Suspending/resuming the machine after booting brings the display back up.

(working with revert)
[ 12.179335] [drm:intel_choose_pipe_bpp_dither], clamping display bpc (was -1) to eDP (6)
[ 12.179337] [drm:intel_choose_pipe_bpp_dither], setting pipe bpc to 8 (max display bpc 6)

(failing)
[ 14.264823] [drm:intel_choose_pipe_bpp_dither], setting pipe bpc to 8 (max display bpc 8)