The following packages have been kept back

Dave Horsfall <[email protected]> Mon, 19 Nov 2018 06:40:51 +1100 (EST)

Newsgroups	gmane.linux.debian.user.laptop
Message-ID	<[email protected]>

Latest Debian 8 (will go to 9 soon) on Acer Aspire E15

     root@debbie:/home/dave# apt-get upgrade
     Reading package lists... Done
     Building dependency tree
     Reading state information... Done
     Calculating upgrade... Done
     The following packages have been kept back:
       firmware-linux-nonfree
     The following packages will be upgraded:
       firmware-atheros
     1 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

What on earth does that mean?  I have "non-free" listed in sources.list
(which this list told me to do).

-- Dave