Would you mind testing this again with 3.13.x? A few fixes went in, especially one that fixes errors setting up displays in NV96 VBIOSes (for HDMI, but your case could be similar). Assuming it still doesn't work help, could you attach a boot (from 3.13.x) with nouveau.debug=PDISP=debug,VBIOS=trace ? Also, could attach a boot from a good kernel (not necessarily the last good rev) with nouveau.debug=debug drm.debug=0xe (this should cause a VBIOS trace from that kernel as well... if it doesn't, I'll have to go back and re-check the kernel parameters for the older version). (This is banking on something being different wrt the vbios, either execution path or perhaps when/how often it is invoked.) Curiously I don't see any opcode 0x44 in your VBIOS. But I think there are some tables I'm actually missing, so perhaps it's there. That's definitely an unknown opcode though -- old or new kernels.