Re: Interesting fix
it can in fact be patched even on the Note 4/etc by periodically flushing unused areas of the chip
I'm curious what you mean by "periodically" here. Note there are potential Spectre1 vulnerabilities between hyperthreads running on the same core, and within even a single process. So, are you going to "flush" on every context switch?
And what are "unused areas"?
with zeros or a PRNG based test pattern such as dummy data from the back camera in dark (ie case) mode
A completely unnecessary complication.
Look, it's nice that people are thinking about these things, but why are you referring to this as an "interesting fix" and prefacing it with "I may have found out how to patch"? There are plenty of people who understand CPU ISAs and microarchitectures who are looking closely at the family of spec-ex + side-channel vulnerabilities. I have no problem with people who don't understand those things making wild-ass guesses, but presenting them as possible fixes (and then getting upvoted, presumably by other people who don't understand them) just muddies the waters. Why not ask whether something is a feasible fix?
1It's not an acronym. Please don't write in block capitals.