Re: Missing release event for Synaptics touchscreen

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

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.
>
>> 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