https://bugs.freedesktop.org/show_bug.cgi?id=56139
--- Comment #21 from Alex Deucher agd5f@yahoo.com --- (In reply to comment #19)
If I followed you correctly, setting bit 24 to "1" disables memory but keeps the CRTC state as it is (hopefully in sync with the monitor). However, what I see when grub2 kicks in with the "gfxpayload=keep" is an unsynced monitor. Sometimes the display will be black, other times it will only appear in the first couple of vertical lines, in others it will be vertically synced but shifted to the right at half or at two third of the screen. In other words, this really seems to be a sync problem. Should I try to combine patch 69113 and patch 69370 with the others?
Are you saying the monitor gets messed up when grub kicks in? I.e., before the OS loads? If so, that sounds like a grub issue.