What does "r8169: can't disable ASPM; OS doesn't have ASPM control" really mean?

r8169 is the name of a module for the Realtek RTL8169 Network Interface Controller which may be included in your /etc/modules file. ASPM stands for Active State Power Management. ASPM enablement can be configured by BIOS or by an OS.

To run the aspm test in the Firmware Test Suite (fwts), open the terminal and run:

sudo apt-get install fwts  
sudo fwts aspm  

To show the verbose results of sudo fwts aspm run the following command:

cat results.log

This test checks the enablement method in ACPI table and verifies the correctness of the ASPM configuration. Visit the Ubuntu Firmware Test Suite/Reference/aspm wiki for information about how to evaluate the results of running sudo fwts aspm .

I just answered my own Question ... I hope it helps others.

After the above 2 suggested (and these first 2 commands explained and restated for some good definitions and clarity):

I will state how to view the log file easy-peasy

Install: Firmware Test Suite (FWTS) is a test suite that performs sanity checks on firmware. It is intended to identify BIOS, UEFI, ACPI and many other errors and if appropriate it will try to explain the errors and give advice to help workaround or fix firmware bugs.with this command:

sudo apt-get install fwts

Run the check:

sudo fwts aspm

And to check the log of this "Check"

cat results.log

I hope this new bit of info helps other!

Mark