From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Fri, 31 May 2013 06:29:44 +0000 (+1000)
Subject: Input: MT - Specify that ABS_MT_SLOT must have a minimum of 0
X-Git-Tag: firefly_0821_release~176^2~541^2~250^2~10^2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=257867dc8d893690c175c1f717f91c3b6d44a63d;p=firefly-linux-kernel-4.4.55.git

Input: MT - Specify that ABS_MT_SLOT must have a minimum of 0

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>
Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
---

diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt
index 2c179613f81b..de139b18184a 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
 ------------------