Ticket #2137 (closed defect: fixed)

Opened 11 years ago

Last modified 10 years ago

stable-tracking lacks touchscreen jitter reduction patch

Reported by: TimoJyrinki Owned by: openmoko-kernel
Priority: normal Milestone:
Component: kernel Version:
Severity: normal Keywords:
Cc: Blocked By:
Blocking: Estimated Completion (week):
HasPatchForReview: no PatchReviewResult:


I'm using self-compiled stable-tracking kernel and it seems the touchscreen is again annoying to use. Most probably something similar to http://git.openmoko.org/?p=kernel.git;a=commit;h=abe8f448547d1bd69ac2963e07e2657f27b79691 has not been ported to the stable-tracking kernel. It seems not to apply as such to the current stable-tracking, but the mentioned patch really helped a lot with the current stable kernel regarding touchscreen usability.

Change History

comment:1 Changed 11 years ago by andy

Tick updated his patch and it is in stable-tracking for 7 hours... do a git pull :-) If it's still broken post more detail.


comment:2 Changed 11 years ago by Treviño

I've just tested this patch and the touchscreen implementation in stable-tracking now seems a little better than the previous one, but it's still buggy (and quite far from the latest stable implementation).

The main bug I've found in my first test (mostly done writing on illume keyboard and using the tick's touch screen test pyhton app) is that quite often happens that the touchscreen send a "push" event to the gui also if I've no finger over it (practically the release event is not sent!).

I got also other errors while scrolling the illume desktop (some applications started while I was still dragging my finger and keep in mind that I've configured illume to start an application only after a double-click! So the touchscreen has sent more than a wrong click).

Up-down-clicks are not always fixed, btw... :(

comment:3 Changed 11 years ago by arhuaco

We're trying to improve this driver. We have improved this driver a little but still we have to make it better.

I'm about to send this patch that makes it easier to modify in order to make it more accurate:


It would be great to hear some feedback.

You should never miss an UP event this this one.

It includes the Jitter detection logic and the same timeout Tick proposed.

Up-down-clicks are not always fixed, btw... :(

What do you mean? That you get erratic coordinates?

There is an issue with erratic clicks, specially with little pressure... We have to explore alternatives to solve this issue. I'm studying one of them (and I have another one pending).

comment:4 Changed 11 years ago by tick

I tested and think arhuaco's patch is pretty good. :-)
But there are still some issue of the bad boundary events.
I think maybe we should discard some events if the input data is too bad. (maybe check the variance of data.)

comment:5 Changed 11 years ago by TimoJyrinki

Right, bad timing on my part :) Thanks for the fix in stable-tracking. I'm now also trying arhuaco's patch, seems good too. Erratic clicks are indeed still possible in some cases, but otherwise very good improvements all in all compared to what was previously in use.

comment:6 Changed 11 years ago by arhuaco

I just sent a patch that should make the driver more usable. It should alleviate the bad clicks issue.


This solution seems to work. Please let us know how it goes.

comment:7 Changed 10 years ago by andy

  • Status changed from new to closed
  • Resolution set to fixed

This stuff is all in andy-tracking and stable branches now, so closing as fixed.

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