HDMI CEC on ODROID-N2+

[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?

--
Stefan