Ignored UDEV rule. :(

# udevadm info --path=/sys/class/drm/card0 --attribute-walk
  looking at device '/devices/pci0000:00/0000:00:01.0/0000:01:00.0/drm/card0':
    KERNEL=="card0"
    SUBSYSTEM=="drm"
    DRIVER==""

  looking at parent device '/devices/pci0000:00/0000:00:01.0/0000:01:00.0':
    KERNELS=="0000:01:00.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="radeon"
    ATTRS{irq}=="47"
    ATTRS{subsystem_vendor}=="0x1043"
    ATTRS{broken_parity_status}=="0"
    ATTRS{class}=="0x030000"
    ATTRS{power_method}=="dynpm" <-- This is after I set it manually.
    ATTRS{consistent_dma_mask_bits}=="40"
    ATTRS{dma_mask_bits}=="40"
    ATTRS{local_cpus}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000003"
    ATTRS{device}=="0x9488"
    ATTRS{power_profile}=="default"
    ATTRS{msi_bus}==""
    ATTRS{local_cpulist}=="0-1"
    ATTRS{vendor}=="0x1002"
    ATTRS{subsystem_device}=="0x1bb2"
    ATTRS{boot_vga}=="1"
    ATTRS{numa_node}=="-1"
    ATTRS{d3cold_allowed}=="1"

  looking at parent device '/devices/pci0000:00/0000:00:01.0':
    KERNELS=="0000:00:01.0"
    SUBSYSTEMS=="pci"
    DRIVERS=="pcieport"
    ATTRS{irq}=="40"
    ATTRS{subsystem_vendor}=="0x1043"
    ATTRS{broken_parity_status}=="0"
    ATTRS{class}=="0x060400"
    ATTRS{consistent_dma_mask_bits}=="32"
    ATTRS{dma_mask_bits}=="32"
    ATTRS{local_cpus}=="00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000003"
    ATTRS{device}=="0x2a41"
    ATTRS{msi_bus}=="1"
    ATTRS{local_cpulist}=="0-1"
    ATTRS{vendor}=="0x8086"
    ATTRS{subsystem_device}=="0x19c7"
    ATTRS{numa_node}=="-1"
    ATTRS{d3cold_allowed}=="0"

  looking at parent device '/devices/pci0000:00':
    KERNELS=="pci0000:00"
    SUBSYSTEMS==""
    DRIVERS==""

Contents of /lib/udev/rules.d/10-local.rules:

KERNELS=="0000:01:00.0",SUBSYSTEMS=="pci", DRIVERS=="radeon", ATTRS{power_method}="dynpm"

Effect on system after reboot:  None. :(.. power_method is still "profile" power_profile is "default" and the fan is full blast.