Re: (EXT) HDMI CEC on ODROID-N2+

[Alexander Stein <alexander.stein@mailbox.org>]

Hi Stefan,

Am Donnerstag, 13. Januar 2022, 15:36:38 CET schrieb Stefan Agner:
> Hi Neil,
> 
> I am trying to use HDMI CEC on ODROID-N2+ using Linux 5.10.91. However,
> I was unsuccessful: As far as I can tell cec-client uses the right
> device (I disabled CONFIG_DRM_DW_HDMI_CEC since my kernel is still
> missing your patch "drm/meson: dw-hdmi: disable DW-HDMI CEC
> sub-driver"). But communication won't work, and dmesg prints timeout
> messages:
> 
> [   68.831253] cec-meson_g12a_ao_cec: message ff 84 20 00 06 timed out
> [   71.134987] cec-meson_g12a_ao_cec: message ff 87 00 15 82 timed out
> [   73.438826] cec-meson_g12a_ao_cec: message f0 timed out
> [   75.742677] cec-meson_g12a_ao_cec: message f0 timed out
> [   78.046555] cec-meson_g12a_ao_cec: message f0 timed out
> [   80.350446] cec-meson_g12a_ao_cec: message f0 timed out
> [   82.654358] cec-meson_g12a_ao_cec: message 11 timed out
> [   84.958285] cec-meson_g12a_ao_cec: message 11 timed out
> [   87.262194] cec-meson_g12a_ao_cec: message 11 timed out
> [   89.566130] cec-meson_g12a_ao_cec: message 11 timed out
> 
> I did a quick test with CoreELEC which uses the 4.9 downstream kernel,
> CEC seems to work there. So it does not seem to be my hardware setup.
> 
> A quick test with the latest Linux 5.16 shows the same errors.
> 
> Do you happen to have an idea? Do you know if HDMI CEC using upstream
> kernels worked at one point on that particular platform?

I'm using Arch Linux on my ODROID-n2 (non-plus) and HDMI CEC works as 
expected.
Currently I'm running a 5.15.13-1-aarch64-ARCH kernel. AFAICS the mentioned 
patch is mainline since v5.14. I can see my TV without issues. I have to add 
that not every cable is suitable for HDMI CEC, I have one where CEC does not 
work (in general).

HTH
Alexander
------
$ cec-ctl --playback
$ cec-ctl -S
Driver Info:
        Driver Name                : meson-ao-cec-g12a
        Adapter Name               : meson_g12a_ao_cec
        Capabilities               : 0x0000011e
                Logical Addresses
                Transmit
                Passthrough
                Remote Control Support
                Connector Info
        Driver version             : 5.15.13
        Available Logical Addresses: 4
        DRM Connector Info         : card 1, connector 32
        Physical Address           : 1.0.0.0
        Logical Address Mask       : 0x0010
        CEC Version                : 2.0
        Vendor ID                  : 0x000c03 (HDMI)
        OSD Name                   : 'Playback'
        Logical Addresses          : 1 (Allow RC Passthrough)

          Logical Address          : 4 (Playback Device 1)
            Primary Device Type    : Playback
            Logical Address Type   : Playback
            All Device Types       : Playback
            RC TV Profile          : None
            Device Features        :
                None

        System Information for device 0 (TV) from device 4 (Playback Device 
1):
                CEC Version                : 1.4
                Physical Address           : 0.0.0.0
                Primary Device Type        : TV
                Vendor ID                  : 0x080046 (Sony)
                OSD Name                   : 'TV'
                Power Status               : Standby

        Topology:

            0.0.0.0: TV
                1.0.0.0: Playback Device 1