This is a couple of important fixes broken out of the series "first step of standardising OPAL_BUSY handling", that prevents the kernel from locking up if the NVRAM or RTC hardware does not respond.
Another one, the console driver, has a similar problem that has also been hit in testing, but that requires larger fixes to the opal console and hvc tty driver that won't make it for 4.17. Thanks, Nick Nicholas Piggin (3): powerpc/powernv: define a standard delay for OPAL_BUSY type retry loops powerpc/powernv: Fix OPAL RTC driver OPAL_BUSY loops powerpc/powernv: Fix OPAL NVRAM driver OPAL_BUSY loops arch/powerpc/include/asm/opal.h | 3 ++ arch/powerpc/platforms/powernv/opal-nvram.c | 7 +++- arch/powerpc/platforms/powernv/opal-rtc.c | 8 +++-- drivers/rtc/rtc-opal.c | 37 +++++++++++++-------- 4 files changed, 37 insertions(+), 18 deletions(-) -- 2.17.0