Bug 175421

Summary:	Greedy detection of Sentelic touchpads by the BYD touchpad driver
Product:	Drivers	Reporter:	Christophe Tordeux (christophe)
Component:	Input Devices	Assignee:	drivers_input-devices
Status:	NEW ---
Severity:	normal
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	v4.6 to v4.8	Subsystem:
Regression:	No	Bisected commit-id:

Description Christophe Tordeux 2016-10-02 15:46:25 UTC

Starting with kernel v4.6, my Sentelic touchpad STL3888_C0 (and probably other Sentelic touchpads are wrongly detected as BYD touchpads by the BYD touchpad driver and lose multitouch features.

This is a bug of the BYD driver in drivers/input/mouse/byd.c because the BYD driver interprets a standard PS/2 protocol answer from the Sentelic touchpad as handshake from a BYD touchpad.

I submitted a patch to fix this but had no reply:
http://www.spinics.net/lists/linux-input/msg46992.html

This is affecting other users see for example this forum post:
https://forum.manjaro.org/t/touchpad-working-in-kernel-4-5-but-not-in-4-6-or-4-7/7714

Comment 1 Christophe Tordeux 2016-10-02 15:48:54 UTC

Sorry, the patch I submitted can be found at this address:
http://www.spinics.net/lists/linux-input/msg46984.html


(In reply to Christophe Tordeux from comment #0)
> Starting with kernel v4.6, my Sentelic touchpad STL3888_C0 (and probably
> other Sentelic touchpads are wrongly detected as BYD touchpads by the BYD
> touchpad driver and lose multitouch features.
> 
> This is a bug of the BYD driver in drivers/input/mouse/byd.c because the BYD
> driver interprets a standard PS/2 protocol answer from the Sentelic touchpad
> as handshake from a BYD touchpad.
> 
> I submitted a patch to fix this but had no reply:
> http://www.spinics.net/lists/linux-input/msg46992.html
> 
> This is affecting other users see for example this forum post:
> https://forum.manjaro.org/t/touchpad-working-in-kernel-4-5-but-not-in-4-6-or-
> 4-7/7714