[PATCH] doc: specify that ABS_MT_SLOT must have a minimum of 0

[PATCH] doc: specify that ABS_MT_SLOT must have a minimum of 0

[Peter Hutterer]

This is effectively already in force through input_mt_init_slots, and uinput
too ignores the actual minimum.

Since slots are a kernel-genenerated axis only, non-zero minimums make
little sense and are likely to cause errors. Better to treat a non-zero
minimum as kernel bug if it ever happens.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---
I admit that sentence looks a bit lost there, if you want to move this
elsewhere to have more exposure I'm happy to do so once I figure out where.

 Documentation/input/multi-touch-protocol.txt | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt
index 2c17961..de139b1 100644
--- a/Documentation/input/multi-touch-protocol.txt
+++ b/Documentation/input/multi-touch-protocol.txt
@@ -80,6 +80,8 @@ Userspace can detect that a driver can report more total contacts than slots
 by noting that the largest supported BTN_TOOL_*TAP event is larger than the
 total number of type B slots reported in the absinfo for the ABS_MT_SLOT axis.
 
+The minimum value of the ABS_MT_SLOT axis must be 0.
+
 Protocol Example A
 ------------------
 
-- 
1.8.2.1

Re: [PATCH] doc: specify that ABS_MT_SLOT must have a minimum of 0

[Benjamin Tissoires]

On Fri, May 31, 2013 at 8:29 AM, Peter Hutterer
<peter.hutterer@who-t.net> wrote:
> This is effectively already in force through input_mt_init_slots, and uinput
> too ignores the actual minimum.
>
> Since slots are a kernel-genenerated axis only, non-zero minimums make
> little sense and are likely to cause errors. Better to treat a non-zero
> minimum as kernel bug if it ever happens.
>
> Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

Acked-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

Adding Dmitry in CC.

Cheers,
Benjamin

Re: [PATCH] doc: specify that ABS_MT_SLOT must have a minimum of 0

[Henrik Rydberg]

On Wed, Jun 12, 2013 at 10:51:56AM +0200, Benjamin Tissoires wrote:
> On Fri, May 31, 2013 at 8:29 AM, Peter Hutterer
> <peter.hutterer@who-t.net> wrote:
> > This is effectively already in force through input_mt_init_slots, and uinput
> > too ignores the actual minimum.
> >
> > Since slots are a kernel-genenerated axis only, non-zero minimums make
> > little sense and are likely to cause errors. Better to treat a non-zero
> > minimum as kernel bug if it ever happens.
> >
> > Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
> 
> Acked-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

Applied, thanks Peter and Benjamin.

Henrik