Touch screen problem with LTS kernel!

[Hüseyin Uçar]

I've been using Android 8.1 with 4.9 kernel for a while, but I noticed that Android boots up faster with LTS kernel. So I started using Android 8.1 with 4.19 LTS kernel, all functions of my computer are running smoothly; but sometimes when I turn on my computer, the touch screen does not work! When the touch screen does not work, I long press the power button to power off and turn it on again, this time the touch screen works. I have never encountered this problem when using Andoid with the 4.9 kernel. I wonder why is this problem caused?

Thanks for your help in advance ...

By the way I use the PC: Sony VAIO Tap 21

[Chih-Wei Huang]

Hüseyin Uçar <huseyi...@mail.com> 於 2020年5月19日 週二 下午5:16寫道：

>
> I've been using Android 8.1 with 4.9 kernel for a while, but I noticed that Android boots up faster with LTS kernel. So I started using Android 8.1 with 4.19 LTS kernel, all functions of my computer are running smoothly; but sometimes when I turn on my computer, the touch screen does not work! When the touch screen does not work, I long press the power button to power off and turn it on again, this time the touch screen works. I have never encountered this problem when using Andoid with the 4.9 kernel. I wonder why is this problem caused?
> Thanks for your help in advance ...
> By the way I use the PC: Sony VAIO Tap 21

Please collect dmesg and lsmod for both
working and non-working cases for comparison.


--
Chih-Wei
Android-x86 project
http://www.android-x86.org

[Hüseyin Uçar]

My dear friend,
First of all, thank you very much for your interest ... The link of the files you want is given below.

https://1drv.ms/f/s!AqEULj33LjmwuEcen57JGjJE3o4z

[Chih-Wei Huang]

Hüseyin Uçar <huseyi...@mail.com> 於 2020年5月20日 週三 上午11:36寫道：

>
> My dear friend,
> First of all, thank you very much for your interest ... The link of the files you want is given below.
>
> https://1drv.ms/f/s!AqEULj33LjmwuEcen57JGjJE3o4z

From the dmesg & lsmod, the touchscreen was detected in both cases:

[ 1.183739] input: USBest Technology SiS HID Touch Controller
Touchscreen as /devices/pci0000:00/0000:00:14.0/usb2/2-3/2-3:1.0/0003:0457:104A.0003/input/input7

I didn't see explicit reason why it didn't work.

However, the logcat was truncated. It doesn't contain information
of EventHub which is used to detect input devices.
Please boot in debug mode and copy /data/log.txt
(which is the full logcat from booting)

Please test the command 'getevent -l' (by root)
and provide the output. (stop it by Ctrl-C)
In particular, check if touchscreen has response when
running the command in the non-working case.

Besides, I saw someone reported that booting android-x86 from
windows boot manager may make touchscreen not work.
Maybe it's the same problem as yours.

[LFOM]

Hello.

Do you have only Android-x8 in this computer? If you are dual-booting with Windows, did you turn off Fast Startup in it? Does it work if turn off the computer for about 15s and then boot directly to Android?

[Hüseyin Uçar]

My dear friend,
I have re-created the following log files for certainty. Could you please review it once more?

https://1drv.ms/f/s!AqEULj33LjmwuErHlJOHaBzwXxy3

[Michael Goffioul]

After boot, if you can manage to get a root terminal on your device (e.g. using ADB), try the following:

    rmmod hid_multitouch

    modprobe hid_multitouch

I remember I used to have a touchscreen problem on my device (eGalax touch device) due to the successive loading of hid_generic (built-in) and hid_multitouch (module). I ended up including hid_multitouch as a built-in module to work around the issue.

Michael.

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[Hüseyin Uçar]

Dear LFOM

I checked the processes you said, the fast boot was on and I turned it off; but the problem still continues! I don't think the problem was caused by fast boot, because when using the 8.1 version with the 4.9 kernel, the fast boot was on and the touch screen was working fine.
Thank you very much for your help in general ...

[Hüseyin Uçar]

Dear Michael Goffioul

I will apply what you say, I will let you know the result after testing.
Thank you for your help...

[Hüseyin Uçar]

Dear Michael Goffioul

The solution you provided didn't work! The problem still continues...

[Hüseyin Uçar]

Dear Chih-Wei Huang

While looking for a solution for the touch screen problem today, I realized that.
After Android boot, the touch screen was not working again and at that time, when I opened the terminal as root and entered the following commands, the touch screen started working.

'modprobe hid_multitouch'
'rmmod hid_multitouch'

Maybe this information helps solve the problem.

[Chih-Wei Huang]

Hüseyin Uçar <huseyi...@mail.com> 於 2020年5月21日 週四 上午4:22寫道：

>
> Dear Chih-Wei Huang
> While looking for a solution for the touch screen problem today, I realized that.
> After Android boot, the touch screen was not working again and at that time, when I opened the terminal as root and entered the following commands, the touch screen started working.
>
> 'modprobe hid_multitouch'

Basically it means you loaded the driver so it works.
However, from the log you provided (in both cases),
the driver has already been loaded.
So I don't see how it solved the problem.

> 'rmmod hid_multitouch'

You unloaded the driver so it stopped working as expected.

Have you tried to load the driver again?

> Maybe this information helps solve the problem.

That only confirms hid_multitouch is the driver of the touchscreen.
However, as I've said before, the driver has been loaded for both cases.
So I still don't have an idea why it doesn't work.

BTW, your new logcat is the same as before (truncated).
I didn't see any info from EventHub (the Android part
used to detect the input devices).

[Michael Goffioul]

On Sun, May 24, 2020 at 9:44 PM Chih-Wei Huang <cwh...@android-x86.org> wrote:

Hüseyin Uçar <huseyi...@mail.com> 於 2020年5月21日 週四 上午4:22寫道：
>
> Dear Chih-Wei Huang
> While looking for a solution for the touch screen problem today, I realized that.
> After Android boot, the touch screen was not working again and at that time, when I opened the terminal as root and entered the following commands, the touch screen started working.
>
> 'modprobe hid_multitouch'

Basically it means you loaded the driver so it works.
However, from the log you provided (in both cases),
the driver has already been loaded.
So I don't see how it solved the problem.

> 'rmmod hid_multitouch'

You unloaded the driver so it stopped working as expected.

Have you tried to load the driver again?

> Maybe this information helps solve the problem.

That only confirms hid_multitouch is the driver of the touchscreen.
However, as I've said before, the driver has been loaded for both cases.
So I still don't have an idea why it doesn't work.

As I reported previously, it's possible the problem is the same I experienced with my eGalax touchscreen. Early in the boot process (before ueventd), hid_generic is loaded for the touchscreen. because the module is built-in. During the ueventd phase, hid_multitouch is loaded for the same touchscreen. It seems that this driver swap ended my touchscreen not to work at all, reloading hid_multitouch made it work again. The symptoms reported by the user seems extremely similar. I solved the issue on my hardware by having hid_multitouch also built-in (so hid_generic is never loaded in the first place).

Michael.