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Subject: Re: [PATCH v3 3/9] input: elants: remove unused axes
From:   Dmitry Osipenko <digetx@gmail.com>
To:     =?UTF-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= <mirq-linux@rere.qmqm.pl>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc:     Henrik Rydberg <rydberg@bitmath.org>,
        James Chen <james.chen@emc.com.tw>,
        Johnny Chuang <johnny.chuang@emc.com.tw>,
        Rob Herring <robh+dt@kernel.org>,
        Scott Liu <scott.liu@emc.com.tw>,
        David Heidelberg <david@ixit.cz>, linux-input@vger.kernel.org,
        linux-kernel@vger.kernel.org
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 <20200426045200.GN125362@dtor-ws> <20200426112150.GA16230@qmqm.qmqm.pl>
 <a9828df8-c974-3bc2-6ecf-962489cf1189@gmail.com>
Message-ID: <489b497b-fd25-fa6b-59c9-9d925c489fe0@gmail.com>
Date:   Sun, 26 Apr 2020 18:41:34 +0300
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26.04.2020 18:39, Dmitry Osipenko пишет:
> 26.04.2020 14:21, Michał Mirosław пишет:
>> On Sat, Apr 25, 2020 at 09:52:00PM -0700, Dmitry Torokhov wrote:
>>> On Mon, Apr 13, 2020 at 03:32:23PM +0200, Michał Mirosław wrote:
>>>> Driver only ever reports MT events. Clear capabilities of all others.
>>> This is not true. input_mt_sync_frame() calls
>>> input_mt_report_pointer_emulation() which does emut single-touch events
>>> for the benefit of older userspace (or userspace that is not interested
>>> in multitouch).
>>
>> Oh, I didn't notice that. Looking at the code, I see that
>> input_mt_init_slots() sets up the emulated axes in this case.
>>
>> Do you need me to update the commitmsg?
> 
> I tried Ubuntu 12.04 that uses ancient libinput (or whatever it was back
> then), which doesn't support MT. Mouse doesn't move at all with this
> patch being applied. Without this patch mouse moves, but it's not usable
> because the cursor's position is wrong, i.e. mouse position doesn't
> match the screen touches.
> 
> This means that input_mt_report_pointer_emulation() doesn't set up
> everything needed for the legacy pointer emulation.
> 

I meant the input_mt_init_slots().