Comment # 19 on bug 900273 from Jon Nelson

Did a lot of research and rebooted a *lot*.
This page:
https://www.kernel.org/doc/Documentation/power/basic-pm-debugging.txt
was especially useful.

It seemed to point to a device problem.
I started blacklisting modules and found

rtsx_usb (and the associated rtsx_usb_ms, rtsx_usb_sdmmc)

*seemed* to be the problem.

A bit of research has indicated that this used to be the rts5139, which I had
previously either blacklist or used special options with. It has *always* been
problematic.

This page:
http://unix.stackexchange.com/questions/155637/rts5139-rtsx-usb-borked-in-3-15
seems to indicate I'm not alone with problems with this hardware.

I'm going to leave it blacklisted, and if the system continues to be stable
(although the WOL rtl1869 stuff would be a nice fix), what - if anything - can
be done to fix this for others (and of course for myself in the future)?