Created attachment 127486 [details]
New dmesg output after manually turning on power management

So Lekensteyn asked me to run a few commands to also shut off the bus the GPU
is on.

If I do so and then proceed by running powertop on battery, intel_pstate
complains about turbo not being available, a usb device disconnects, a while
later Nouveau resumes kernel object trees, Bluetooth reconnects and nouveau
suspends again.

The commands are:
# echo auto > /sys/bus/pci/devices/0000\:00\:1c.4/power/control 
# grep .
/sys/bus/pci/devices/0000:0{0:1c.4,1:00.0}/power/{control,runtime_status}

The latter returns auto, suspended, auto, suspended before running powertop,
and on, active, auto, suspended after running powertop.