HDMI CEC LibreELEC not working

LIbreELEC 11.0.3
Raspberry Pi 4

HDMI-CEC has been working for years with Raspberry Pi 2, 3 and just the generic plastic case.

Now, it’s not working at all.

Same telly, same HDMI cable, new Pi 4, Argon One case, fresh LibreELEC 11.0.3 install. Pulse-Eight CEC Adaptor loads as normal.

No CEC signals passing through from the remote to the Pi.

Elsewhere is this forum I see someone had a similar problem and it turned out to be fixed when Argon support sent a replacement daughter board. Is that the only solution?

I tried running some CEC utils via SSH but I don’t have a lot of experience with them. It just looks like they’re telling me everything’s broken!

cec-client

No device type given. Using 'recording device'
CEC Parser created - libCEC version 4.0.7
no serial port given. trying autodetect:
 path:     /dev/cec0
 com port: Linux

opening a connection to the CEC adapter...
DEBUG:   [              76]     Broadcast (F): osd name set to 'Broadcast'
DEBUG:   [              76]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [              76]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [              76]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [              76]     could not open a connection (try 1)
DEBUG:   [              76]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            1076]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            1076]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            1076]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            1076]     could not open a connection (try 2)
DEBUG:   [            1076]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            2076]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            2076]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            2076]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            2076]     could not open a connection (try 3)
DEBUG:   [            2076]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            3077]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            3077]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            3077]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            3077]     could not open a connection (try 4)
DEBUG:   [            3077]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            4077]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            4077]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            4077]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            4077]     could not open a connection (try 5)
DEBUG:   [            4077]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            5077]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            5077]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            5077]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            5077]     could not open a connection (try 6)
DEBUG:   [            5077]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            6077]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            6077]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            6077]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            6077]     could not open a connection (try 7)
DEBUG:   [            6077]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            7078]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            7078]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            7078]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            7078]     could not open a connection (try 8)
DEBUG:   [            7078]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            8078]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            8078]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            8078]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            8078]     could not open a connection (try 9)
DEBUG:   [            8078]     CLinuxCECAdapterCommunication::Close - m_fd=-1
DEBUG:   [            9078]     CLinuxCECAdapterCommunication::Open - m_fd=3 bStartListening=1
ERROR:   [            9078]     CLinuxCECAdapterCommunication::Open - ioctl CEC_S_MODE failed - errno=16
DEBUG:   [            9078]     CLinuxCECAdapterCommunication::Close - m_fd=3
ERROR:   [            9078]     could not open a connection (try 10)
DEBUG:   [            9078]     CLinuxCECAdapterCommunication::Close - m_fd=-1
unable to open the device on port Linux
NOTICE:  [           10079]     connection opened
ERROR:   [           10079]     could not start CEC communications

cec-client /dev/cec1

No device type given. Using 'recording device'
CEC Parser created - libCEC version 4.0.7
opening a connection to the CEC adapter...
DEBUG:   [               0]     Broadcast (F): osd name set to 'Broadcast'
ERROR:   [            3504]     error opening serial port '/dev/cec1': Couldn't lock the serial port
ERROR:   [            3504]     could not open a connection (try 1)
ERROR:   [            6340]     error opening serial port '/dev/cec1': Couldn't lock the serial port
ERROR:   [            6340]     could not open a connection (try 2)
ERROR:   [            8230]     error opening serial port '/dev/cec1': Couldn't lock the serial port
ERROR:   [            8230]     could not open a connection (try 3)
ERROR:   [            9490]     error opening serial port '/dev/cec1': Couldn't lock the serial port
ERROR:   [            9490]     could not open a connection (try 4)
unable to open the device on port /dev/cec1
NOTICE:  [           10495]     connection opened
ERROR:   [           10495]     could not start CEC communications

cec-ctl

Driver Info:
        Driver Name                : vc4_hdmi
        Adapter Name               : vc4-hdmi-0
        Capabilities               : 0x0000010e
                Logical Addresses
                Transmit
                Passthrough
                Connector Info
        Driver version             : 6.1.38
        Available Logical Addresses: 1
        DRM Connector Info         : card 0, connector 32
        Physical Address           : f.f.f.f
        Logical Address Mask       : 0x0000
        CEC Version                : 1.4
        Vendor ID                  : 0x001582 (Pulse-Eight)
        OSD Name                   : ''
        Logical Addresses          : 1 (Allow Fallback to Unregistered)

          Logical Address          : Not Allocated
            Primary Device Type    : Record
            Logical Address Type   : Record
            All Device Types       : Record
            RC TV Profile          : None
            Device Features        :
                None