Re: [PATCH v9 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation

From: Sebastian Reichel
Date: Sun Feb 19 2017 - 15:15:31 EST


Hi,

On Sun, Feb 19, 2017 at 01:07:26PM +0100, H. Nikolaus Schaller wrote:
> I don't really remember when we noticed it first. Maybe it was
> back in tslib times some years ago where setting the sensitivity
> threshold made problems. We then carried along our patch for a
> long time in our local repo (and modified it several times) and
> only started upstreaming some months ago. [...]
>
> AFAIK, GIMP and for example https://sourceforge.net/projects/xournal/ appear
> to be able to handle X pressure, but I haven't running and tested either one
> on our devices. Pressure is used in such drawing tools to simulate that some
> physical pens make wider strokes on higher pressure.
>
> This seems to indicate that X can handle pressure in a non-boolean way, but rarely does.
> Especially I think the usual menu, click, drag, scroll gestures are only based
> on BTN_TOUCH status and not on ABS_PRESSURE. So it is rarely noticed to make
> a difference.

ok.

> >>> I suggest to put the resistance vs pressure thing in its own patch,
> >>> that also fixes tsc200x-core and merge it to linux-next after the
> >>> merge window.
>
> Ok. I will propose a patch.

Thanks. I suggest to add this in the patch description:

While this patch changes the values reported to userspace,
ABS_PRESSURE is used rarely by userspace. Most software only
relies on BTN_TOUCH (boolean), which is not affected by this
patch. Some graphics software makes use of the interface and
does not work correctly with the currently used inverted
behaviour.

-- Sebastian

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