Hm, what does the following show? cat /sys/bus/pci/devices/0000:02:00.0/power/control # GPU cat /sys/bus/pci/devices/0000:02:00.0/power/runtime_status # GPU cat /sys/bus/pci/devices/0000:02:00.0/power/runtime_usage # GPU cat /sys/bus/pci/devices/0000:02:00.0/power/runtime_active_kids # GPU cat /sys/bus/pci/devices/0000:02:00.1/power/control # HDA cat /sys/bus/pci/devices/0000:02:00.1/power/runtime_status # HDA cat /sys/bus/pci/devices/0000:02:00.1/power/runtime_usage # HDA cat /sys/bus/pci/devices/0000:02:00.1/power/runtime_active_kids # HDA I can't see anything in dmesg that the HDA controller is bound to a driver. What does the following show? ls -l /sys/bus/pci/devices/0000:02:00.1/driver