Nathan Chancellor <nathan@xxxxxxxxxx> writes: > Hi Michael, > > Thanks for the workaround and sorry this has come to bite us :/ > > On Fri, Mar 03, 2023 at 12:16:56AM +1100, Michael Ellerman wrote: >> For the -mtune option clang doesn't accept power10/9/8, instead it >> accepts pwr10/9/8. That will be fixed in future versions of clang, but >> the kernel must support the clang versions in the wild. >> >> So add support for the "pwr" spelling if clang is in use. >> >> Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx> > > I think that should actually be > > Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> I guess yeah. >> BugLink: https://github.com/ClangBuiltLinux/linux/issues/1799 >> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> > > Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> Thanks. >> --- >> arch/powerpc/platforms/Kconfig.cputype | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> Need to confirm the clang <= 16 statement is correct. > > Currently, this is indeed the case. It is possible that Nemanja's patch > will get applied to release/16.x before 16.0.0 final but it might not. > > We can always update it later. I think we do want to push to get that > patch applied because I forgot that it is only in 16.0.0 that '-mtune' > starts to do something on PowerPC: > > https://github.com/llvm/llvm-project/commit/1dc26b80b872a94c581549a21943756a8c3448a3 > > Prior to that change, '-mtune' was accepted but did nothing. It is only > once it was hooked up to the backend that we got the spew of warnings. I > think that warrants us trying to get Nemanja's patch into 16.0.0, which > may allow us to drop this workaround altogether... Aha OK, I missed that the warning was new in 16. I'll sit on this for now then until we know if that change will make it into clang 16. cheers
