Re: [PATCH] Input: elan_i2c - Change the hover event from MT to ST

From: Benjamin Tissoires
Date: Wed Jul 08 2015 - 19:25:10 EST


On Wed, Jul 8, 2015 at 7:11 PM, Dmitry Torokhov
<dmitry.torokhov@xxxxxxxxx> wrote:
> On Wed, Jul 08, 2015 at 06:58:36PM -0400, Benjamin Tissoires wrote:
>> On Tue, Jul 7, 2015 at 2:06 PM, Dmitry Torokhov
>> <dmitry.torokhov@xxxxxxxxx> wrote:
>> > On Tue, Jul 07, 2015 at 01:37:14PM +0800, duson wrote:
>> >> We want the hover event like BTN_LEFT, even no contract object,
>> >> it still can be reported to upper OS system.
>> >>
>> >> Signed-off by: Duson Lin <dusonlin@xxxxxxxxxx>
>> >
>> > Applied, thank you.
>>
>> Sorry for waking up too late but I am not sure we want this patch.
>>
>> Why do we need to remove the ABS_MT_DISTANCE bits? I can understand
>> that we would want to to have ABS_DISTANCE for the pointer emulation,
>> but removing the per-finger information does not make much sense.
>> libinput knows now how to deal with per-finger hovering through
>> ABS_MT_DISTANCE, and you are just breaking the touchpad/screens with
>> this patch.
>
> Because the device does not provide per-finger information about
> hovering. It can only tell that there is "something" hovering over the
> surface, but it doe snot provide the data that there are 2 fingers
> hovering or that finger 1 was in contact but now is hovering, etc.
>

OK, I see now. I have then no opinion on the patch itself (not sure
any client uses ABS_DISTANCE) :)

Cheers,
Benjamin
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