Re: [PATCH 0/9] platform/surface: aggregator: Improve target/source handling in SSH messages

From: Benjamin Tissoires
Date: Thu Dec 08 2022 - 13:27:06 EST


On Thu, Dec 8, 2022 at 5:49 PM Maximilian Luz <luzmaximilian@xxxxxxxxx> wrote:
>
> On 12/8/22 17:24, Benjamin Tissoires wrote:
> > On Thu, Dec 8, 2022 at 5:03 PM Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
> >>
> >> Hi Maximilian,
> >>
> >> On 12/2/22 23:33, Maximilian Luz wrote:
> >>> We have some new insights into the Serial Hub protocol, obtained through
> >>> reverse engineering. In particular, regarding the command structure. The
> >>> input/output target IDs actually represent source and target IDs of
> >>> (what looks like) physical entities (specifically: host, SAM EC, KIP EC,
> >>> debug connector, and SurfLink connector).
> >>>
> >>> This series aims to improve handling of messages with regards to those
> >>> new findings and, mainly, improve clarity of the documentation and usage
> >>> around those fields.
> >>>
> >>> See the discussion in
> >>>
> >>> https://github.com/linux-surface/surface-aggregator-module/issues/64
> >>>
> >>> for more details.
> >>>
> >>> There are a couple of standouts:
> >>>
> >>> - Patch 1 ensures that we only handle commands actually intended for us.
> >>> It's possible that we receive messages not intended for us when we
> >>> enable debugging. I've kept it intentionally minimal to simplify
> >>> backporting. The rest of the series patch 9 focuses more on clarity
> >>> and documentation, which is probably too much to backport.
> >>>
> >>> - Patch 8 touches on multiple subsystems. The intention is to enforce
> >>> proper usage and documentation of target IDs in the SSAM_SDEV() /
> >>> SSAM_VDEV() macros. As it directly touches those macros I
> >>> unfortunately can't split it up by subsystem.
> >>>
> >>> - Patch 9 is a loosely connected cleanup for consistency.
> >>
> >> Thank you for the patches. Unfortunately I don't have time atm to
> >> review this.
> >>
> >> And the next 2 weeks are the merge window, followed by 2 weeks
> >> of christmas vacation.
> >>
> >> So I'm afraid that I likely won't get around to reviewing
> >> this until the week of January 9th.
> >>
> >>> Hans, Jiri, Benjamin, Sebastian: While patch 8 ("platform/surface:
> >>> aggregator: Enforce use of target-ID enum in device ID macros") touches
> >>> multiple subsystems, it should be possible to take the whole series
> >>> through the pdx86 tree. The changes in other subsystems are fairly
> >>> limited.
> >>
> >> I agree that it will be best to take all of this upstream through the
> >> pdx86 tree. Sebastian thank you for the ack for patch 8/9.
> >>
> >> Jiri or Benjamin may we have your ack for merging patch 7/9 + 8/9
> >> through the pdx86 tree ?
> >
> > I can give you an ack for taking those through your tree, but I can
> > not review the patches themselves because I was only CC-ed to those 2,
> > and so was linux-input. Given that SSAM_SSH_TID_KIP is not in my
> > current tree I assume it comes from this series.
> >
> > Anyway, enough ranting :)
>
> Apologies for that. I should have included you in the CC on at least
> patch 2 as well, which introduces this symbol.

No need to apologize. There is a tight balance between not annoying
people with too many emails and then having those people wanting to
have all of the series :)

I have enough trust in Hans to know that when he reviewed the series,
he did it correctly.

>
> FWIW, here's the patchwork link to this series:
>
> https://patchwork.kernel.org/project/platform-driver-x86/list/?series=701392

thanks!

Cheers,
Benjamin