Re: [PATCH 12/12] Input: docs: add more details on the use of BTN_TOOL

From: Benjamin Tissoires
Date: Mon Feb 14 2022 - 06:17:09 EST


Hi Peter,


Looks like you commented on v1, and I made some changes in the v2 :)

On Wed, Feb 9, 2022 at 7:22 AM Peter Hutterer <peter.hutterer@xxxxxxxxx> wrote:
>
> On Wed, Jan 26, 2022 at 05:18:32PM +0100, Benjamin Tissoires wrote:
> > The HID core stack used to be very relaxed considering the BTN_TOOL_*
> > usage. With the recent commits, we should now enforce to have only one
> > tool at a time, meaning that we can now express that requirement in the
> > docs.
> >
> > Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
> > ---
> > Documentation/input/event-codes.rst | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst
> > index b24ae7d292cc..41b1fa647dab 100644
> > --- a/Documentation/input/event-codes.rst
> > +++ b/Documentation/input/event-codes.rst
> > @@ -137,7 +137,10 @@ A few EV_KEY codes have special meanings:
> > code should be set to a value of 1. When the tool is no longer interacting
> > with the input device, the BTN_TOOL_<name> code should be reset to 0. All
> > trackpads, tablets, and touchscreens should use at least one BTN_TOOL_<name>
> > - code when events are generated.
> > + code when events are generated. Likewise all trackpads, tablets, and
> > + touchscreens should export only one BTN_TOOL_<name> at a time. It is
>
> s/export/set to nonzero/ to avoid any ambiguity with setting the evbit on the
> device vs setting the value to nonzero.

I can carry this change in the v3.

>
> > + however accepted to switch tool in one EV_SYN frame by setting the old
> > + BTN_TOOL_<name> at a value of 0 and the new one at 1.
>
> I would even s/accepted/recommended/ but this LGTM to me, thanks.

In v2 I used recommended, but I turned the meaning the other way
around. In the v2 it reads:
"To not break existing userspace, it is recommended to not switch tool
in one EV_SYN frame but first emitting the old BTN_TOOL_<name> at 0,
then emit one SYN_REPORT and then set the new BTN_TOOL_<name> at 1."

So maybe I should use "accepted" in v3?

>
> Acked-by: Peter Hutterer <peter.hutterer@xxxxxxxxx>

Do I keep your acked-by in the v2/3?

Cheers,
Benjamin