Re: [PATCH v2 0/9] Add support for Microsoft Surface System Aggregator Module

From: Leon Romanovsky
Date: Sun Dec 06 2020 - 06:42:46 EST


On Sun, Dec 06, 2020 at 11:41:46AM +0100, Hans de Goede wrote:
> Hi,
>
> On 12/6/20 11:33 AM, Leon Romanovsky wrote:
> > On Sun, Dec 06, 2020 at 11:04:06AM +0100, Hans de Goede wrote:
>
> <snip>
>
> >> But there is a difference between being careful and just nacking
> >> it because no new UAPI may be added at all (also see GKH's response).
> >
> > I saw, the author misunderstood the Greg's comments.
>
> Quoting from patch 8/9:
>
> "
> +==============================
> +User-Space EC Interface (cdev)
> +==============================
> +
> +The ``surface_aggregator_cdev`` module provides a misc-device for the SSAM
> +controller to allow for a (more or less) direct connection from user-space to
> +the SAM EC. It is intended to be used for development and debugging, and
> +therefore should not be used or relied upon in any other way. Note that this
> +module is not loaded automatically, but instead must be loaded manually.
> "
>
> If I'm not mistaken that seems to be pretty much what Greg asked for.

Right, unless you forget the end of his request.
"
The "joy" of creating a user api is that no matter how much you tell
people "do not depend on this", they will, so no matter the file being
in debugfs, or a misc device, you might be stuck with it for forever,
sorry.
"

So I still think that exposing user api for a development and debug of device
that has no future is wrong thing to do.

Thanks

>
> Regards,
>
> Hans
>