I get an error message which is absolutely the last thing before poweroff that is NOT ever reported in kern.log nor by dmesg.
It reads like this: 48.255417 DMAR: DRHD: handling fault status reg 2 48.255457 DMR: [DMA Read] request device [00:17.0] PASID ffffffff fault addr aboe9000 [fault reason 06] PTE read access is not set 48.255557 reboot: Power down What pack age would this be in so I can file a bug? Note, similar problems have been reported but this is unique: 1) It only occurs at power off but not on reboot. No other handling fault errors reported by dmesg 2) Nothing is shown in any kern.log files probably because it is too late to write anything John