11-05-2020, 12:03 PM
Good news! In the meantime, I've switched from the factory-installed Debian to Manjaro ARM, and one of the results is that the laptop battery can now actually be charged when the laptop is connected to the factory charger and subjected to light use, i.e., low CPU load, WiFi turned off, Bluetooth off, etc. I always had the same Gigabit Ethernet USB 3.0 dongle connected. Under the same conditions, the factory-installed Debian made the same laptop unusable by ending up with completely discharged battery and the laptop abruptly turned off.
It isn't Debian's fault by any means, but there's no doubt that the Rockchip-provided Linux kernel that's shipped with Debian has some weirdness in it (i.e., "just get the SoC out the door" type of code) that caused unnecessarily high power consumption. The Linux kernel shipped with Manjaro shows how the same thing can be done properly. Good job, Manjaro!
As an example, the laptop running Manjaro can actually recharge the battery from about 73% to about 92% while under the above-described light load. That was by no means possible with the factory-installed Debian, the battery would pretty much never recharge unless the same laptop was completely turned off.
As another example, the bottom cover of the laptop is significantly less warm when running Manjaro, under the same load.
However, running a "make -j6" inside the Linux kernel source tree causes the battery to drain rapidly, despite the laptop being connected to the factory charger. That clearly shows that the PineBook Pro's charging subsystem is unable to provide enough power to support 100% CPU load, which is not good.
I am going to continue my investigation about possible hardware modifications that would improve the charging subsystem, and I will report my findings back here.
It isn't Debian's fault by any means, but there's no doubt that the Rockchip-provided Linux kernel that's shipped with Debian has some weirdness in it (i.e., "just get the SoC out the door" type of code) that caused unnecessarily high power consumption. The Linux kernel shipped with Manjaro shows how the same thing can be done properly. Good job, Manjaro!
As an example, the laptop running Manjaro can actually recharge the battery from about 73% to about 92% while under the above-described light load. That was by no means possible with the factory-installed Debian, the battery would pretty much never recharge unless the same laptop was completely turned off.
As another example, the bottom cover of the laptop is significantly less warm when running Manjaro, under the same load.
However, running a "make -j6" inside the Linux kernel source tree causes the battery to drain rapidly, despite the laptop being connected to the factory charger. That clearly shows that the PineBook Pro's charging subsystem is unable to provide enough power to support 100% CPU load, which is not good.
I am going to continue my investigation about possible hardware modifications that would improve the charging subsystem, and I will report my findings back here.
