On boot my RHEL 6 machine shows a few errors just after kernel selection but before decrypting the disk:
pnp 00:0c: can't evaluate _CRS: 8 [drm] nouveau 0000:01:00.0: failed to load fuc409c
I'm not sure what these mean or how to fix them. The machine is able to continue booting fine and appears to operate without issue except that it will only shutdown, reboot stalls after all processes are halted. Not sure if that's related or not.
The machine is a 2011 Dell Precision M4600.