Let me just point out, that Windows does indeed blacklist drivers that don't use ASPM correctly. Probably to prevent crashes.
If you run , you get a report about the power usage of your system.
On my PC, USB suspending and ASPM doesn't work:
I think in my case, it's the ATI Catalyst drivers that cause ASPM to not work. I guess it could also be bios related, but my motherboard is otherwise high quality.
Platform Power Management Capabilities:PCI Express Active-State Power Management (ASPM) Disabled
PCI Express Active-State Power Management (ASPM) has been disabled due to a known incompatibility with the hardware in this computer.