Comment # 18 on bug 104362 from nmr

Created attachment 143124 [details]
dmesg during reboot/recovery

On the basis that it may be shader induced I repro'd a similar hang with dxvk
(v0.95-5-gcc38412). 

FWIW here's dmesg during subsequent GPU recovery (which fails :( ) and reboot
(which hangs.) It appears hung on a DMA, and/or hung doing a modeset, acquiring
the modeset lock.