Re: Missing release event for Synaptics touchscreen

[Arek Burdach <arek.burdach@gmail.com>]

Hi Benjamin,

On 16.05.2017 11:46, Arek Burdach wrote:
>
>
> On 16.05.2017 10:18, Benjamin Tissoires wrote:
>> On Mon, May 15, 2017 at 8:45 PM, Arek Burdach 
>> <arek.burdach@gmail.com> wrote:
>>> Hi Benjamin,
>>>
>>> I found out what was wrong in the change that you've provided:
>>>
>>> On 12.05.2017 16:28, Benjamin Tissoires wrote:
>>>
>>> +       if (td->mtclass.quirks & MT_QUIRK_STICKY_FINGERS)
>>> +               mod_timer(&td->release_timer, msecs_to_jiffies(250));
>>>   }
>>>
>>> Should be:
>>>
>>> mod_timer(&td->release_timer, jiffies + msecs_to_jiffies(100));
>> Right, thanks!
>>
>>> Delay should be added to current jiffies value. Also I found out 
>>> that 250 ms
>>> is too long delay - xserver recognize such a delay as a drag 
>>> gesture. Using
>>> 100 ms everything works perfectly!
>> Does 160 ms works too?
> 160 ms works too but I have a feeling that values closer to 200 ms 
> gives quite a laggy experience so I'd suggest to keep value closer to 
> 100 ms. Beside that I haven't seen situation that "normal" syn_report 
> have been repored after longer delay than 30 ms. Mean value is 9 ms 
> and 95 pp ~10 ms (tested by drags with evemu-record)
>
>> I'd rather have 10 times the maximum time
>> between 2 reports than 6.25 times it :)
>> We can use 96 ms if 160 doesn't work.
> In fact 100 ms it is exactly 6 times the maximum time between 2 
> reports, because 60 Hz frequency gives 16,(6) ms period
>
>>> What do you think that should be changed
>>> more in the patch to make it ready for being submitted as an 
>>> official patch?
>> Not much actually. I need to wrote down a commit message, sign it
>> (your sign-off-by can also be added given that you debugged it), and
>> that should be it.

Do you planning to submit this change? I think that other users would be 
glad to take advantage of this fix :-)
Or do you want me to do it on your behalf?


>>
>>> I thought about some unit tests, but can't find any for hid drivers 
>>> also I
>> I have a test suite that can emulate hid devices and inject them in
>> hid-multitouch. The setup is a little bit manual, so I'll try to run
>> it today and see if there are differences with or without the patch.
> Ok, waiting for signed patch

Cheers,
Arek