https://bugs.freedesktop.org/show_bug.cgi?id=56139
--- Comment #36 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #33)
Here is a partial kernel.log tracking what is going on at boot with some debug printk in evergreen_mc_stop() and evergreen_mc_resume(). Strangely, only one crtc is saved as enabled in the _stop function, but four are restored in the _resume function. Pretty sure it's not the problem we are looking for, but it is abnormal since only one crtc should be restored on resume. This is a bug by itself showing a problem in the save(stop)/restore(resume) mechanism.
I should have said "... but six are restored..." instead of "... but four are restored..." I also made a small error in a debug string, but it doesn't change the read value. If you have any question on my patch, let me know.
That issue is fixed in attachment 69573 which is already upstream.