Disabling PCIE device ASPM?

Hi,

I'm having some issues with the Agere PCIE Firewire controller in my iMac. I wanted to try the experiment of disabling ASPM (link power management) for that particular link.

1) Is there an OS X app/utility that allows for control of ASPM (in general, or on particular links)?
2) If the answer to the above is 'No' .. does anyone recommend an app for accessing PCI(E) config space to manually disable ASPM? Or even if it's read-only, I'd atleast like to look at the link settings.

thanks