OTG Connectivity LG V20



  • 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!


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