Phantom Touches, Ghost touches, Invisible finger

[M1cha]

Mi2 here

 

[Irish Jimmy]

Mi 2S here

 

[deini]

Well, being two different models being produced with a difference of a few months, I think it will hardly be a hardware issue. Let's hope Xiaomi will provide a solution.

 

[M1cha]

I contacted xiaomi and they need a dmesg log when that happens. So as soon as it starts happening u should dump it

 

[StefanoA]

I contacted xiaomi and they need a dmesg log when that happens. So as soon as it starts happening u should dump it

Good!

but.... how to do that ?

 

[M1cha]

adb shell su -c dmesg > dmesg.log

 

[ingbrzy]

or *#*#BUG#*#*

 

[StefanoA]

or *#*#BUG#*#*

that is much simpler

ok, I will try to do that and post here the dump file

 

[Acid]

As I remember Ive also got that bug but it was many months ago. My MI-2 has almost a year and I've never did full wipe. That bug I had once and I think it started after unlocking lockscreen and entering google talk with opening keyboard.

 

[ingbrzy]

I contacted xiaomi and they need a dmesg log when that happens. So as soon as it starts happening u should dump it

bugreport from one our user...

 

[regent89]

I'd like you to check, if the problem with phantom touches is related with headphones plugged in or after plugging off.

Please reboot your phone and don't plug headphones and check if phantom touches are still present

 

[ingbrzy]

another one...

 

[peelaa]

I have the same problem with my mi2s. The phone is only a few days old, bought from ibuygou and happend straight out of the box. It seems to happen more if I long press on the screen.
I really hope this is a firmware issue.

 

[M1cha]

I think it is a firmware issue because issue seems to be new. never had this issue a year ago.
And I've installed latest miui a few times I'm not running opensource kernel only.

The crazy thang is that all touchscreens(atmel and synaptic) have these issues.

 

[Wubbajacm]

Getting my mi2s in sometime next week, let's hope it's ok. I'll post the result here. I hope xiaomi picks up on this and fixes the problem

 

[M1cha]

since this problem did not happen in the past(at least for me), we could check if this problem still persists if we downgrade all bootloaders.

 

[cypher]

go two mi2, and never experienced anything like this.
but I'll have a mi2s next week, and I'll report here if I should find something like this.
meanwhile, I'll keep an eye on this thread..

 

[M1cha]

I downgraded my base system(tz, sbl*, aboot, modem, rpm) to 3.1.18(I bought my phone when this was the latest).
We'll see if this helps.

 

[deini]

I remember a line in build.prop file on some ROMs that may have some effect

touch.pressure.scale=0.3

This was the value for a CM10 ROM for my HTC Sensation . Maybe you can try different values to see if it helps.

 

[M1cha]

wow. Why I didn't think about that. Nexus4 has such a calibration, too.
I'm using nexus4 calibration settings, now. I hope it will work.

 

[M1cha]

I now know a way to easily raise this problem.
Just download the app "Multitouch Tester" and randomly touch your screen with 10 fingers at the same time.

If you touch the screen with two fingers you'll see 1 or 2 phantom touches.

 

[StefanoA]

I now know a way to easily raise this problem.
Just download the app "Multitouch Tester" and randomly touch your screen with 10 fingers at the same time.
If you touch the screen with two fingers you'll see 1 or 2 phantom touches.

Nice news!

I tried but cannot reproduce the problem,
I'll try again the multitouch check when problem happens again

 

[M1cha]

It seems there are two problems.
1) missing firmware flash feature of opensource kernel. This is why I always had the problem. A reboot into miui fixed this.
2) I dunno if xiaomi's cm10 has the firmware flash feature but if yur firmware is ok there still can be some issues. This could be fixed with a touchconfig. I'll make a flashable zip to install n4 config so you can try if this works for you.

 

[Wubbajacm]

Mi2S is in and've been playing with it all evening. I'm happy to report no phantom touches as of yet. Installed the latest and greatest 3.10.18 + gapps almost straight away using the MiRecovery method.

 

[M1cha]

Here is a possible fix. Please do only report if you have the problem on MIUI or stock-aosp(4.1) rom.
Opensource kernel's problems can be caused by the firmware issue and can can be fixed by a reboot into miui.
I don't know how the closed source kernel of cm10.2 works.