Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx> writes: > 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. Apologies for not sending there. My (18 month ago self) bad. -- Stewart Smith OPAL Architect, IBM.