Android-x86_64 experience

[Josef Schabasser]

Hi!

I have a Samsung XE700T1C-A02DE and I use Android-x86 since version 4.4 on it.

I got the screen backlight working using "acpi_backlight=video" kernel command line for linux kernel 4.0+ and this modification of build.prop file:
> #
> # Brightness Fix for Samsung XE700
> #
> backlight.brightness_file=/sys/class/backlight/acpi_video0/brightness
> backlight.max_brightness_file=/sys/class/backlight/acpi_video0/max_brightness

This tablet also has an integrated Huawei MU733 3G modem.
I tried using "PPP Widget 3". It detects the modem ports (ttyUSBx) but as soon as it tries to communicate with the modem using AT commands, the modem port gets disconnected from the system. Here is some dmesg output:

[ 3.116628] usb 2-1.5: GSM modem (1-port) converter now attached to ttyUSB0
[ 3.116696] usb 2-1.5: GSM modem (1-port) converter now attached to ttyUSB1
[ 3.116759] usb 2-1.5: GSM modem (1-port) converter now attached to ttyUSB2
[ 1370.786823] option1 ttyUSB0: GSM modem (1-port) converter now disconnected from ttyUSB0

The exact same happens to the built-in GPS receiver using "GNSS Commander".
dmesg output:
[ 3.146303] usb 2-1.6: cp210x converter now attached to ttyUSB3
[ 3.146358] usb 3-3.1: cp210x converter now attached to ttyUSB4
[ 336.077861] cp210x ttyUSB3: cp210x converter now disconnected from ttyUSB3

Did someone experience the same issue on another device?
Does someone know how to fix this problems?

Best regards,
Joe