[Skiboot] [PATCH] Skip OCCs for chip that has occ_functional set to false

Stewart Smith stewart at linux.vnet.ibm.com
Mon Sep 7 10:11:39 AEST 2015

Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com> writes:
> On 09/03/2015 09:07 AM, Stewart Smith wrote:
>> In some simulation environments, we simulate a system close to an
>> ibm-fsp system but with a crucial difference: we don't simulate OCCs.
>> This means that for a P8 (well, a simulated one) that looks like it's
>> part of a ibm-fsp system, we'd wait around for about a minute to be
>> asked to start OCCs and for the OCCs to start. Obviously, this would
>> never happen and we'd hit the OCC initialization timeout (correctly)
>> logging an error.
>> However, in this simulation environment, it isn't an error as the
>> required information to work out it isn't an error is (at least now)
>> provided in hdat under 'OCC Functional State'.
>> Previously, the ibm,occ-functional-state property was just passed
>> through the device tree to the host through the XSCOM node and
>> skiboot ignored it.
>> This patch takes note of occ-functional-state and skips waiting for
>> OCCs on any chips that have been marked as having non functional
>> OCC.
> In non-simulation environment,
> 1)Can any of the chips be marked as having non-functional OCC?
> 2)Can the processor chips be marked with different occ-functional-state?

I'd love to know, but getting documentation on what this "occ functional
state" seems much harder than it should be.

The (internal) bug for this is mostly me asking what that field means
and if it does in fact mean this.

So far, the complete documentation we have is:
"OCC Functional State (4 bytes)"
"if zero, OCC not functional"

and that's it... :/

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