[patch 1/1] TOUCHSCREEN: S3C24XX touchscreen driver from Arnaud Patard.

Ben Dooks ben at simtec.co.uk
Thu Nov 19 12:48:24 EST 2009


Dmitry Torokhov wrote:
> On Thu, Nov 19, 2009 at 01:52:36PM +0000, Daniel Silverstone wrote:
>> On Thu, Nov 19, 2009 at 11:34:40AM +0000, Ben Dooks wrote:
>>>>> +		input_report_key(ts.input, BTN_TOUCH, 1);
>>>>> +		input_report_abs(ts.input, ABS_PRESSURE, 1);
>>>> No fake pressure events please, BTN_TOUCH should be enough.
>>> I'd have to check, IIRC tslib needs these to function properly.
>> Indeed it does -- otherwise it won't work.  Yes you could try going around and
>> patching TSLIB but so many people use it that it is principle-of-least-surprise
>> to produce pressure events.
>>
>>>>> +	ts.input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
>>>>> +	input_set_abs_params(ts.input, ABS_X, 0, 0x3FF, 0, 0);
>>>>> +	input_set_abs_params(ts.input, ABS_Y, 0, 0x3FF, 0, 0);
>>>>> +	input_set_abs_params(ts.input, ABS_PRESSURE, 0, 1, 0, 0);
>>>> Drop ABS_PRESSURE.
>>> ok, see above.
>> The same applies here -- claim ABS_PRESSURE or tslib won't operate with the
>> touchscreen.
>>
>> While it is tempting to be 100% exactly correct to what the hardware reports
>> (which is only TOUCH not PRESSURE) it is preferable to work with the software
>> which the majority of people use -- namely tslib.
>>
>> I would strongly argue against removing the ABS_PRESSURE stuff personally,
>> despite it being essentially a lie.

ok, i'll remove it and anyone who can't be bothered to update their
tslib can hack in their own solution if they really care about it.

> And I would strongly argue that you just need to update your tslib,
> especially given the fact that this issue was dealt with there about a
> year ago.  And if you really need that fix to be in released (read
> 'tagged') version of tslib - please speak to its maintainer.

> Why everyone thinks that it is a good idea to pile workarounds for
> software issues in the kernel but updating the other parts of software
> stack is a big no-no?

it can be much more difficult to update a userland than to hack the
kernel...



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