On Mon, 2016-06-27 at 22:42 +0200, Gerhard Pircher wrote: > This patch series reminds me of a long-standing issue with the > AmigaOne platform code, which would have to clear the coherence > (M) flag for every memory mapping to avoid lockups (especially > on G4 CPUs) - as you can read in the comment below your patch > above. > > Now the follow-up code in amigaone/setup.c to clear the > corresponding CPU feature flag is essentially dead code (it used > to work with a second call of do_feature_fixups() before the > handling of the CPU_FTR_NEED_COHERENT flag was changed/inverted > somewhere around v2.6.30). Also it doesn't seem to fix all > deadlocks, as e.g. KVM virtual machines can still inject memory > mappings with the M flag set AFAICT. > > Now I wonder, if there is a reasonably clean way to clear the M > flag in all hardware page table and BAT entries without defacing > generic kernel code too much. Any ideas?
Other than a compile time option ? Do we know where the lockups come from btw ? A problem with the northbridge ? Cheers, Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
