Patch 1 explains most of the reasoning. Patch 1+2 and possibly 4 (just that we've seen a bug caused by the RTC driver but not yet one caused by NVRAM) could be backported as bugfixes, in most other cases the changes are inconsequential or unlikely to be a problem.
Thanks, Nick Nicholas Piggin (6): powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops powerpc/powernv: OPAL RTC driver standardise OPAL_BUSY loops powerpc/powernv: OPAL platform standardise OPAL_BUSY loops powerpc/powernv: OPAL NVRAM driver standardise OPAL_BUSY delays powerpc/powernv: OPAL dump support standardise OPAL_BUSY delays powerpc/xive: standardise OPAL_BUSY delays arch/powerpc/include/asm/opal.h | 3 + arch/powerpc/platforms/powernv/opal-dump.c | 4 +- arch/powerpc/platforms/powernv/opal-nvram.c | 7 +- arch/powerpc/platforms/powernv/opal-rtc.c | 6 +- arch/powerpc/platforms/powernv/opal.c | 8 +- arch/powerpc/platforms/powernv/setup.c | 16 ++- arch/powerpc/sysdev/xive/native.c | 193 ++++++++++++++++------------ drivers/rtc/rtc-opal.c | 33 +++-- 8 files changed, 163 insertions(+), 107 deletions(-) -- 2.16.3