Interesting! Did the flicker fade after some time?
More details about my experience. When the flicker started, I rebooted into windows and observed that the problem persisted. I shutdown windows and kept the machine off for maybe 2-3 minutes. Then rebooted into linux (another kernel version), the flicker was still occurring. Then left the machine on, then noticed the problem seemed to be less and less visible, over a period of about 2-3 hours until it was barely noticeable. Then shutdown and packed the machine. When turning it back on, no more flicker.
The fact that it persisted across reboots/shutdown should give hints to someone who knows how the firmware+hardware deals with the screen+backlight power. Is GPD open enough to provide schematics or additional details to help us figure this out?
It would be very interesting to get a similar report from a windows user… or alternatively, for a few weeks to pass without any windows user reporting such a problem, which given the number of windows users, would lead us to believe that the linux vs windows difference in handling screen power off is the place to check.
At this point, we have reports from 3 different users running 3 different distros (though probably very similar kernel versions). The ubuntu mate p2max may also become popular and we’ll have more reports, “hopefully”.