linux-kernel - Re: 答复: 答复: 答复: [PATCH] input: alps-fix the issue the special alps trackpoint do not work.

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Date:   Thu, 23 May 2019 16:01:54 +1000
From:   Peter Hutterer <peter.hutterer@...-t.net>
To:     Pali Rohár <pali.rohar@...il.com>
Cc:     Xiaoxiao Liu <xiaoxiao.liu-1@...alps.com>,
        dmitry.torokhov@...il.com, Hui Wang <hui.wang@...onical.com>,
        XiaoXiao Liu <sliuuxiaonxiao@...il.com>,
        "linux-input@...r.kernel.org" <linux-input@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Xiaojian Cao <xiaojian.cao@...alps.com>,
        "zhangfp1@...ovo.com" <zhangfp1@...ovo.com>
Subject: Re: 答复: 答复: 答复: [PATCH] input: alps-fix the issue the
 special alps trackpoint do not work.

On Wed, May 22, 2019 at 09:40:30AM +0200, Pali Rohár wrote:
> On Wednesday 22 May 2019 07:30:43 Xiaoxiao Liu wrote:
> > Hi Pali,
> > 
> > Ok, and cannot you set ALPS_DUALPOINT flag based on that
> > alps_check_is_trackpoint() result and then update
> > alps_process_packet_ss4_v3() code to supports also
> > V8 trackpoint packets?
> > --> Yes, we can do like so, when we use the v8 method to process the trackpoint , the mouse speed is not ideal.
> >       Then we choose the standard mouse driver.
> 
> Mouse speed is something which is configurable. Have you configured it
> somehow? Also there is libinput project should handle these settings
> more properly.
> 
> Adding Peter Hutterer, maintainer of libinput to loop. I think he could
> help with this problem.

libinput has a quirk for a magic multiplier on trackpoints. it was the only
solution I found that came close to "working" given that every device seems
to provide some other random magic data. Doc for it is here:
https://wayland.freedesktop.org/libinput/doc/latest/trackpoint-configuration.html

There are also different speeds depending on which xorg driver you'd use (or
libinput/Wayland), so a "mouse speed is not ideal" is almost a guarantee,
given a large enough variety of setups :) That's why we have the speed
toggle, but I'm happy to hear any suggestions on how to make the trackpoint
more useful (in libinput anyway).

> I do not think it is a good idea to force back to generic PS/2 mouse
> driver for touchpads and trackpoints. Native drivers for touchpads and
> trackpoints supports multitouch, absolute reporting and lot of other
> things... Also calculation of mouse speed from absolute positions on
> touchpads can be more easily fixed as from emulated relative movements.

Yeah, agree. Using PS/2 mouse drivers means you lose *all* the extra
features touchpads have like palm detection, tapping, scrolling, gestures,
etc.

Cheers,
   Peter

> 
> Dmitry, what is your opinion about this problem? What should psmouse.ko
> do in this situation? Disallow usage of absolute mode and force bare
> PS/2 relative mode?