What is supported is ... what is supported. Wherein the manufacturers assert that their hardware supports Linux, OEMs assert that it supports Linux, Linux developers assert that it is supported, or user reports assert that it is supported. The old school way is to plug the exact model of hardware and the word "linux" into your favorite search engine but there are actual hardware compatibility lists too.

For something to be "stock" has no meaning whatsoever and one doesn't have to guess if something is supported one can usually find out.