Hi, On 02/08/2016 at 11:50:16 +1000, Stewart Smith wrote: > According to the OPAL docs: > https://github.com/open-power/skiboot/blob/skiboot-5.2.5/doc/opal-api/opal-rtc-read-3.txt > https://github.com/open-power/skiboot/blob/skiboot-5.2.5/doc/opal-api/opal-rtc-write-4.txt > OPAL_HARDWARE may be returned from OPAL_RTC_READ or OPAL_RTC_WRITE and this > indicates either a transient or permanent error. > > Prior to this patch, Linux was not dealing with OPAL_HARDWARE being a > permanent error particularly well, in that you could end up in a busy > loop. > > This was not too hard to trigger on an AMI BMC based OpenPOWER machine > doing a continuous "ipmitool mc reset cold" to the BMC, the result of > that being that we'd get stuck in an infinite loop in opal_get_rtc_time. > > We now retry a few times before returning the error higher up the stack. > > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Stewart Smith <stewart@xxxxxxxxxxxxxxxxxx> > --- > drivers/rtc/rtc-opal.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > Just a note to let you know that this patch should have gone through my tree but it was not sent to linux-rtc or me. I guess what happened is that Michael cleaned up the Linux PPC patchwork queue. -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com