Comment 64 for bug 1158689

Well, given that it doesn't work on the blob makes it sound like you have some sort of funkiness in your hardware. One unsubstantiated theory is that the vdec clock is *disabled*, and pcrypt is hooked up to that clock. Or perhaps that clock is somehow broken. It'd be interesting to see whether the old blob version can be made to work, but I wouldn't spend _too_ much time on it. May be easy to do with an older livecd or something.

So, in order to completely disable PCRYPT without patching your system you can boot with "nouveau.config=PCRYPT=0" in your kernel cmdline (since 3.7, I think). It will also disallow userspace from using PCRYPT, which is probably for the best if it's really broken. (Whereas just commenting it out there prevents a very specific use-case of it.)

With a pre-3.13 kernel, you can also try adding nouveau.perflvl_wr=7777 nouveau.perflvl=1 which will force reclocking to happen on boot (to level '1' which in your case is comparable to what you had been booting to anyways), and just might get PCRYPT going (if the clock theory is right). Or hang your machine. (Or both!) With 3.13 you'll need to apply a patch to enable the reclocking functionality. [Obviously test this theory without the PCRYPT disable stuff.]

BTW, to people who are not Andreas: Please post a full kernel log of a boot with nouveau in a semi-recent kernel, that should reveal whether you guys are all having the same issue or not.