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

H. Nikolaus Schaller
2017-02-20T16:51:18Z

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Hi Pavel,

> Am 19.02.2017 um 23:39 schrieb Pavel Machek <pavel@ucw.cz>:
>
> Hi!
>
>>>> And note that I am not making things different from others in tree,
>>>> I am making the tsc2007 right (incl. following the touchscreen
>>>> bindings which define the touchscreen size in "Pixels").
>>>
>>> Your touch screen is not in any way special, so it has to behave in
>>> the same way others do.
>>>
>>
>> I agree, the tsc2007 (=what the interface provides to userspace) should
>> not behave special, for example it should behave like the virtual
>> touchscreen (=what the interface provides to userspace) virtualbox
>> gives. No need to be calibrated. Well, the internals are different. But
>> that is what the kernel is good for, abstract such things.
>> Conclusion: It cannot be totally wrong behavior to have pixel values
>> there.
>
> It is not "totally wrong". But it is useless code that should not be
> in kernel. Calibration certainly does not belong to single
> _driver_.

It belongs to driver + attached panel. I.e. hardware. Which the kernel
or driver should IMHO abstract from as good as possible.

> Feel free to submit driver

For what? The tsc2007 driver already exists.

> but keep the calibration code out
> of tree...

It is the really important patch to add this.

>
> But if you have userspace that depends on touchscreen to be
> calibrated... that _is_ wrong.

User-space people and real users have the opposite opinion. They
prefer if a touch is plug&play. I.e. without need for calibration.

When did you last time re-calibrate the heads of your hard disk in
user-space?

BR and thanks,
Nikolaus

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