Hey,
which kernel did you use for the provided Hummingboard image (wheezy)? Is it a self-patched linux-linaro or the latest from solidrun (linux-fslc)?
My test tells me, that it is the one from solidrun as I'm not able to use PCI on my HB pro. I've recognized it using the current devel of OpenELEC which also uses kernel 3.14.60 from solidrun. An older version of OpenELEC (e.g. 6.0.3) or Armbian (eg. 4.4 using 3.14.53) works quite good.
The PCI driver and the dts changed quite a lot between those kernel repositories. Do you have any suggestions how to fix that? My tries all ended in a boot hang (black screen).