On Sun, Jan 07, 2018 at 06:51:26PM +0100, christophe leroy wrote: > Le 07/01/2018 à 17:43, Segher Boessenkool a écrit : > >On Sun, Jan 07, 2018 at 05:23:13PM +0100, christophe leroy wrote: > >>Today, Linux kernel includes a workaround for CPU6 ERRATA on the 8xx > >>powerpc. > >> > >>This ERRATA exists on the 801, the 823, the 855/860 before revision C.0 > >>It doesn't concern any modern versions of the 8xx, neither the 860 past > >>and including rev C.0, nor the 866 nor the 885 > >> > >>This workaround complicates the TLBmiss and TLBerror handlers and make > >>the code more and more unreadable. > >> > >>Since this workaround addresses very old versions of the 8xx, I'd like > >>to get rid of it. Do you see any good reason to keep it today ? If not I > >>will come with a cleanup patch in the coming weeks. > > > >What is "very old"? It'll help if you give some indication. > > CPU6 bug is already announced fixed in rev C.0 in revision 1.4 of the > ERRATA document, issued in August 2000.
And that is the newest chip that had the bug? Wow, very old indeed then. > >Removing the workarounds is fine by me, of course... Maybe make it fail > >to boot though, with an error message? Someone *will* try to run it on > >an old system, *especially* if you think no one would. > > Ok, will see how we can do that. It means identifying each revision of > the chip. If it is *that* old you may not have to bother... Up to the maintainers of course. Segher
