Re: [PATCH 0/9] Add support for Microsoft Surface System Aggregator Module

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 11/15/20 8:21 PM, Maximilian Luz wrote:
> Hello,
> 
>   N.B.: the following text is mostly a repeat of cover letter from the
>   previous RFC for the uninitiated, which can be found at
> 
>   https://lore.kernel.org/linux-serial/20200923151511.3842150-1-luzmaximilian@gmail.com/
> 
>   See "Changes" below for an overview of differences between the RFC and
>   this patchset. I hope I have addressed all comments from that in this
>   version, thank you again for those.
> 
> The Surface System Aggregator Module (we'll refer to it as Surface
> Aggregator or SAM below) is an embedded controller (EC) found on various
> Microsoft Surface devices. Specifically, all 4th and later generation
> Surface devices, i.e. Surface Pro 4, Surface Book 1 and later, with the
> exception of the Surface Go series and the Surface Duo. Notably, it
> seems like this EC can also be found on the ARM-based Surface Pro X [1].

<snip>

> This patch-set can also be found at the following repository and
> reference, if you prefer to look at a kernel tree instead of these
> emails:
> 
>   https://github.com/linux-surface/kernel tags/s/surface-aggregator/v1
> 
> Thanks,
> Max

Thank you for your work on this. It would be great if we can get better
support for the Surface line in the mainline kernel.

Since a lot of people have already commented on this series I think that
you have enough feedback to do a v2 addressing that feedback right? 

For now I'm going to assume that you will do a v2 addressing the
initial round of comments and not review this myself (IOW I'll review
this when v2 is posted).

Let me know if you see things differently.

Regards,

Hans





> [1]: The Surface Pro X is, however, currently considered unsupported due
>      to a lack of test candidates and, as it seems, general lack of
>      Linux support on other parts. AFAIK there is an issue preventing
>      serial devices from being registered, on which the core driver in
>      this series is build on, thus there is no way to even test that at
>      this point. I'd be happy to work out any issues regarding SAM on
>      the Pro X at some point in the future, provided someone can/wants
>      to actually test it.
> 
> [2]: https://github.com/linux-surface/surface-aggregator-module
> [3]: https://github.com/linux-surface/linux-surface
> 
> 
> Note: This patch depends on
> 
>   [PATCH v4] platform/surface: Create a platform subdirectory for
>              Microsoft Surface devices
> 
> which can be found at
> 
>   https://lore.kernel.org/platform-driver-x86/20201009141128.683254-1-luzmaximilian@gmail.com/
> 
> and is currently in platform-drivers-x86/for-next.
> 
> 
> Changes from the previous RFC (overview):
>  - move to platform/surface
>  - add copyright lines
>  - change SPDX identifier to GPL-2.0+ (was GPL-2.0-or-later)
>  - change user-space interface from debugfs to misc-device
>  - address issues in user-space interface
>  - fix typos in commit messages and documentation
>  - fix some bugs, address other issues
> 
> Changes regarding specific patches (and more details) can be found on
> the individual patch.
> 
> 
> Maximilian Luz (9):
>   platform/surface: Add Surface Aggregator subsystem
>   platform/surface: aggregator: Add control packet allocation caching
>   platform/surface: aggregator: Add event item allocation caching
>   platform/surface: aggregator: Add trace points
>   platform/surface: aggregator: Add error injection capabilities
>   platform/surface: aggregator: Add dedicated bus and device type
>   docs: driver-api: Add Surface Aggregator subsystem documentation
>   platform/surface: Add Surface Aggregator user-space interface
>   platform/surface: Add Surface ACPI Notify driver
> 
>  Documentation/driver-api/index.rst            |    1 +
>  .../surface_aggregator/client-api.rst         |   38 +
>  .../driver-api/surface_aggregator/client.rst  |  394 +++
>  .../surface_aggregator/clients/cdev.rst       |   85 +
>  .../surface_aggregator/clients/index.rst      |   21 +
>  .../surface_aggregator/clients/san.rst        |   44 +
>  .../driver-api/surface_aggregator/index.rst   |   21 +
>  .../surface_aggregator/internal-api.rst       |   67 +
>  .../surface_aggregator/internal.rst           |   50 +
>  .../surface_aggregator/overview.rst           |   76 +
>  .../driver-api/surface_aggregator/ssh.rst     |  343 +++
>  MAINTAINERS                                   |   13 +
>  drivers/platform/surface/Kconfig              |   39 +
>  drivers/platform/surface/Makefile             |    3 +
>  drivers/platform/surface/aggregator/Kconfig   |   65 +
>  drivers/platform/surface/aggregator/Makefile  |   17 +
>  drivers/platform/surface/aggregator/bus.c     |  424 +++
>  drivers/platform/surface/aggregator/bus.h     |   27 +
>  .../platform/surface/aggregator/controller.c  | 2557 +++++++++++++++++
>  .../platform/surface/aggregator/controller.h  |  288 ++
>  drivers/platform/surface/aggregator/core.c    |  831 ++++++
>  .../platform/surface/aggregator/ssh_msgb.h    |  201 ++
>  .../surface/aggregator/ssh_packet_layer.c     | 2009 +++++++++++++
>  .../surface/aggregator/ssh_packet_layer.h     |  175 ++
>  .../platform/surface/aggregator/ssh_parser.c  |  229 ++
>  .../platform/surface/aggregator/ssh_parser.h  |  157 +
>  .../surface/aggregator/ssh_request_layer.c    | 1254 ++++++++
>  .../surface/aggregator/ssh_request_layer.h    |  142 +
>  drivers/platform/surface/aggregator/trace.h   |  625 ++++
>  .../platform/surface/surface_acpi_notify.c    |  884 ++++++
>  .../surface/surface_aggregator_cdev.c         |  299 ++
>  include/linux/mod_devicetable.h               |   18 +
>  include/linux/surface_acpi_notify.h           |   39 +
>  include/linux/surface_aggregator/controller.h |  832 ++++++
>  include/linux/surface_aggregator/device.h     |  430 +++
>  include/linux/surface_aggregator/serial_hub.h |  659 +++++
>  include/uapi/linux/surface_aggregator/cdev.h  |   58 +
>  scripts/mod/devicetable-offsets.c             |    8 +
>  scripts/mod/file2alias.c                      |   23 +
>  39 files changed, 13446 insertions(+)
>  create mode 100644 Documentation/driver-api/surface_aggregator/client-api.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/client.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/clients/cdev.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/clients/index.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/clients/san.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/index.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/internal-api.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/internal.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/overview.rst
>  create mode 100644 Documentation/driver-api/surface_aggregator/ssh.rst
>  create mode 100644 drivers/platform/surface/aggregator/Kconfig
>  create mode 100644 drivers/platform/surface/aggregator/Makefile
>  create mode 100644 drivers/platform/surface/aggregator/bus.c
>  create mode 100644 drivers/platform/surface/aggregator/bus.h
>  create mode 100644 drivers/platform/surface/aggregator/controller.c
>  create mode 100644 drivers/platform/surface/aggregator/controller.h
>  create mode 100644 drivers/platform/surface/aggregator/core.c
>  create mode 100644 drivers/platform/surface/aggregator/ssh_msgb.h
>  create mode 100644 drivers/platform/surface/aggregator/ssh_packet_layer.c
>  create mode 100644 drivers/platform/surface/aggregator/ssh_packet_layer.h
>  create mode 100644 drivers/platform/surface/aggregator/ssh_parser.c
>  create mode 100644 drivers/platform/surface/aggregator/ssh_parser.h
>  create mode 100644 drivers/platform/surface/aggregator/ssh_request_layer.c
>  create mode 100644 drivers/platform/surface/aggregator/ssh_request_layer.h
>  create mode 100644 drivers/platform/surface/aggregator/trace.h
>  create mode 100644 drivers/platform/surface/surface_acpi_notify.c
>  create mode 100644 drivers/platform/surface/surface_aggregator_cdev.c
>  create mode 100644 include/linux/surface_acpi_notify.h
>  create mode 100644 include/linux/surface_aggregator/controller.h
>  create mode 100644 include/linux/surface_aggregator/device.h
>  create mode 100644 include/linux/surface_aggregator/serial_hub.h
>  create mode 100644 include/uapi/linux/surface_aggregator/cdev.h
>