Re: [Linuxwacom-discuss] How to find out what is really supported on 056a:00e6

[Ping C. <pin...@gm...>]

On Mon, Dec 3, 2012 at 11:08 AM, Maximilian Federle <
max...@go...> wrote:

> Am 03.12.2012 19:55, schrieb Ping Cheng:
>
>  The kernel patch was submitted by Manoj Iyer [1] last year. I do not
>> have an E6 system to work on. But I did acknowledge the patch since I
>> think considering E6 as a 2 finger touch device is a reasonably
>> decision. We do not support bounding box in X driver anyway.
>>
>> What steps did you use to see the "5 touches supported" message? I'd
>> like to see if there is anything we can do about it.
>>
>
> I used the following: http://paste.ubuntu.com/**1408532/<http://paste.ubuntu.com/1408532/>
>
> Observe the last line: "Max number of touches: 5"


As Jason mentioned before, we found an issue for max_touches in X driver.
Without my patch (not merged yet), I could see different number of max
touches for the same touch device. However, "Max number of touches: 5" for
E6 is quite an incident, especially if you always see 5. There might be
something we need to look deeper.

Do you mind to apply a few patches to the latest xf86-input-wacom and test
the driver on your system? Let me know and I'll forward the patches
offline. I am curious about the output.


>  Could you, if it doesn't take too much time, elaborate on how realistic
> you think an (optional) option is, to map the "fake" touches to x/y values
> of the touches we can really track?
>

I do not think faking x/y values is a good way to go. Once there are more
than two fingers, we only get a bounding box with number of touches.

If your interest is mainly in gestures, modifying the kernel driver to
report touches as ABS_TOOL_*TAP events for all five fingers and let
xf86-input-synaptics driver take care of your device can be a solution.
Again, someone has to work on the code.


> For example I see that the latest head of easystroke (a gesture
> recognizer) started implementing multitouch support. So if I can record
> gestures with these additional fake touches I can at least use the
> additional fingers for easy/basic 3-5 finger gestures. I don't think it
> would matter then if two fingers are directly above each other.
>

We could fake touches for special use. But those fake touches won't be
accepted by upstream, especially won't be in the kernel driver.

Maybe I'm getting this all wrong though. How do you receive information
> about the number of fingers in the driver? Would you calculate them by
> "guessing" from the bounding box of the touch, or can you read the number
> directly from the hardware?
>

We get the number of touches from the firmware. That is reliable.

Ping