[Skiboot] [PATCH v2 00/11] MBOX Protocol: Onwards to V3

Stewart Smith stewart at linux.vnet.ibm.com
Mon Dec 4 16:58:34 AEDT 2017

Cyril Bur <cyril.bur at au1.ibm.com> writes:
> Firstly, let me apologise for the amount of rework in this series.
> Ultimately the goal here was really the last three patches.
> Unfortunately in the process of writing them I started thinking about
> some of the problems in version 2.
> The easiest to address is a bug that came up in testing V3 which is
> that if opening a window fails, skiboot will assume that the previously
> opened window is still valid this is incorrect. Patch 2 address this
> problem.
> Then I got to thinking about errors and timeouts. It turns out that
> currently if mbox-flash decides a message times out, it will not be
> able to send anymore due to the lpc-mbox driver needing a response for
> every message it sent out - patch 4 deals with this. However after
> writing a significantly less invasive fix I realised that the entire
> handling of timeouts/retries/resends/late responses was racey. So a
> much simpler version of patch 4 became patches 3-6.
> Then there was some extra version 2 stuff that wasn't necessary but is
> nice to have - patch 7.
> Then on to actually implementing version 3 - at the time of writing
> version 2 Suraj did suggest what has become patch 8. This actually
> makes the version 3 patch - patch 9 very easy.
> The final patch is an extended, reworked and even more improved
> version of the tests I sent with version 2 (which weren't merged at
> the time)
> One final note: this series passes all the tests I can throw at it
> however I do not have reliable access to a MBOX version 3 Daemon
> running on real hardware. Suraj has been kind enough to use (very)
> similar versions of this series in his testing and he informs me that
> there are no problems, however this exact code has never run on real
> hardware.

I seed the v3 spec doc has been merged into the thingy repo. As
discussed on Slack, i'll await a respin of the series before looking to

Stewart Smith
OPAL Architect, IBM.

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