Created attachment 204501 [details] journalctl log part of shutdown On a completely fresh installed archlinux install with just base and base-devel installed (UEFI64 dual boot with win10) running shutdown or systemctl poweroff will result in all services being stopped and partitions unmounted but wont fully shutdown. Eventually I see some INFO: task kworker/5:12:116 blocked for more than 120 seconds. not tainted 4.4.1-2 ARCH #1 messages popping up. looking into journalctl I was able to find a call trace and the folks in #systemd informed me to file a bug here. Attached is the part of journalctl running after shutdown is called.
I also just noticed lspci completely hangs without producing any output and I can't stop the process. (eventually it starts printing the same blocked > 120s message)
I managed to resolve it by installing proprietary nvidea drivers. now lspci produces output as expected
i suppose, then, that this is a bug in the open source nvidia driver.