On Tue, 2016-08-02 at 01:50:16 UTC, Stewart Smith wrote:

According to the OPAL docs: https://github.com/open-power/skiboot/blob/skiboot-5.2.5/doc/opal-api/opal-r... https://github.com/open-power/skiboot/blob/skiboot-5.2.5/doc/opal-api/opal-r... 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@vger.kernel.org Signed-off-by: Stewart Smith stewart@linux.vnet.ibm.com

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/5b8b58063029f02da573120ef4dc90

cheers