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

[Benjamin Tissoires <benjamin.tissoires@redhat.com>]

On Thu, Dec 8, 2022 at 5:03 PM Hans de Goede <hdegoede@redhat.com> 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 :)

If you think the patches are OK, they are really small concerning the
HID part, so feel free to take them through your tree Hans.

Cheers,
Benjamin

>
> Regards,
>
> Hans
>
>
>
>
> > Maximilian Luz (9):
> >   platform/surface: aggregator: Ignore command messages not intended for
> >     us
> >   platform/surface: aggregator: Improve documentation and handling of
> >     message target and source IDs
> >   platform/surface: aggregator: Add target and source IDs to command
> >     trace events
> >   platform/surface: aggregator_hub: Use target-ID enum instead of
> >     hard-coding values
> >   platform/surface: aggregator_tabletsw: Use target-ID enum instead of
> >     hard-coding values
> >   platform/surface: dtx: Use target-ID enum instead of hard-coding
> >     values
> >   HID: surface-hid: Use target-ID enum instead of hard-coding values
> >   platform/surface: aggregator: Enforce use of target-ID enum in device
> >     ID macros
> >   platform/surface: aggregator_registry: Fix target-ID of base-hub
> >
> >  .../driver-api/surface_aggregator/client.rst  |  4 +-
> >  .../driver-api/surface_aggregator/ssh.rst     | 36 ++++-----
> >  drivers/hid/surface-hid/surface_hid.c         |  2 +-
> >  drivers/hid/surface-hid/surface_kbd.c         |  2 +-
> >  .../platform/surface/aggregator/controller.c  | 12 +--
> >  .../platform/surface/aggregator/ssh_msgb.h    |  4 +-
> >  .../surface/aggregator/ssh_request_layer.c    | 15 ++++
> >  drivers/platform/surface/aggregator/trace.h   | 73 +++++++++++++++++--
> >  .../platform/surface/surface_aggregator_hub.c |  8 +-
> >  .../surface/surface_aggregator_registry.c     |  2 +-
> >  .../surface/surface_aggregator_tabletsw.c     | 10 +--
> >  drivers/platform/surface/surface_dtx.c        | 20 ++---
> >  .../surface/surface_platform_profile.c        |  2 +-
> >  drivers/power/supply/surface_battery.c        |  4 +-
> >  drivers/power/supply/surface_charger.c        |  2 +-
> >  include/linux/surface_aggregator/controller.h |  4 +-
> >  include/linux/surface_aggregator/device.h     | 50 ++++++-------
> >  include/linux/surface_aggregator/serial_hub.h | 40 ++++++----
> >  18 files changed, 191 insertions(+), 99 deletions(-)
> >
>