2021–10–26:
Pinephone HDMI hot-plug-detection HW bug fixed
The HDMI HPD HW bug I discovered previously that breaks USB-C Alt-DP mode
was confirmed by the product team.
I've took some time to figure out a software based workaround to signalling
hot-plug detection signal (HPD) from ANX7688 HDMI bridge to HDMI PHY inside the
SoC and the rest of the DRM driver stack.
If you had issues with Alt-DP stopping at DP state 0x03 and not
going further and was not able to use Pinephone with a HDMI dock connected to a
monitor, now you should be able to with my 5.15 Linux kernel.