HDMI hang when hotplugging on J4125 (GLK)
I've been trying to track down an issue which I can reproduce on several J4125 boxes here.
I'm a Slackware user, so I have only two stock kernels to jump between that I've narrowed it to. But 5.4.84 was working. I can pull out HDMI, and stick it back in either port, and it will correctly show the console. However since 5.10.1 (and still currently on 5.15.2), the HDMI output seems to get caught in kernel somewhere.
The screen turns on, but does not display anything. Trying the other port, the screen does not even recognise a signal.
If I do the same under X, then X will lock-up completely, and the process can not be killed.
dmesg does not show anything around the time of hotplugging.
The system does not shut down after the HDMI failure also.
I have several Apollo Lake and Gemini Lake boxes here, so can do some testing on different chipsets if required. There are quite many kernel changes between 5.4.84 and 5.10.1, so any advice on where to start looking would be appreciated.