User:Dsimic/PinePhone Screen Issue

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Known issues

Some forum members reported screen delamination on their PinePhones, which was not caused by rough handling or mechanical damage to the phone. The delamination happens in the upper half of the screen, which clearly suggests that the root cause is the heat generated by the A64 SoC, which is underneath that part of the screen. See this forum thread for further information.

As a preventative measure, more restrictive thermal throttling can be applied to the A64 SoC in PinePhones. First, the default thresholds for CPU thermal throttling on a PinePhone can be checked using the following commands:

grep . /sys/class/thermal/thermal_zone0/trip_point_*_temp
grep . /sys/class/thermal/thermal_zone0/trip_point_*_type

Needless to say, the default thresholds allow the CPU and the upper third of the screen to become very hot even under light CPU load. The following commands can be used to configure more restrictive CPU thermal throttling:

echo 45000  > /sys/class/thermal/thermal_zone0/trip_point_0_temp
echo 65000  > /sys/class/thermal/thermal_zone0/trip_point_1_temp
echo 100000 > /sys/class/thermal/thermal_zone0/trip_point_2_temp

The unit for all numeric values is millidegree Celsius. Those commands can be executed either manually, from a shell script, or some sysctl rules can be configured to perform the settings upon each boot.

Of course, those thresholds can be tweaked until the desired reduction of temperature is achieved. Current CPU temperature can be checked using the following command:

cat /sys/class/thermal/thermal_zone0/temp

Further information can be found in these two documents from the Linux kenel source: