OTG Connectivity LG V20

alexbarryw

Hi All,

I recently installed Ubuntu Touch on an LG V20 H918 following the guide:
https://forums.ubports.com/topic/3367/lg-v20-t-mobile-h918/2?_=1584115563495

I'm hoping for help / insight towards getting OTG connectivity working. When connected to a PC (Ubuntu 18.04.4) the device is not available in the file manager and not detected by mtp-detect. Checking the status of the otg_default settings in the /sys/class directory shows:

root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=none
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=device

so the data_role has changed, but nothing else. The device does display a charging icon on the top status bar, despite the power_role not having set to "sink"
I can ssh into the device at phablet@10.15.19.82 so data across the usb cable is working. Setting dual_role_mode to ufp does not have an effect. If I set dual_role_mode incorrectly to dfp, the system resets itself to ufp, and also toggles power_role to "sink"

root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# ls
data_role  device  mode  power  power_role  subsystem  supported_modes  uevent
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=none
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=device
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# echo ufp > mode
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=ufp
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=device
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# echo dfp > mode
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=ufp
DUAL_ROLE_POWER_ROLE=sink
DUAL_ROLE_DATA_ROLE=device

Once unplugged, everything resets as expected:

root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=none
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=none

When plugged into any device were the phone should operate in dfp mode, I cannot get the power_role to toggle to "source"
The following is with a keyboard plugged in via an OTG cable:

root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=none
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=none
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# echo dfp > mode
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=dfp
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=none
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# echo ufp > mode
root@ubuntu-phablet:/sys/class/dual_role_usb/otg_default# cat uevent
DUAL_ROLE_NAME=otg_default
DUAL_ROLE_MODE=none
DUAL_ROLE_POWER_ROLE=none
DUAL_ROLE_DATA_ROLE=none

So the system won't remain improperly in ufp mode, but also won't change power_role or data_role to match dfp mode.
Even during active ssh across the usb cable, lsusb displays nothing.

What other information should I be looking for? Any advice is appreciated!