Lately I was forced to use rkdeveloptool to resolve a problem with borked SPI flash on my Pinebook Pro. The tool was working ok just couple of months before so I didn't expect any problems. I forced the laptop into maskrom mode and tried to download db and here is what happened:
#rkdeveloptool db rk3399_loader_spinor_v1.15.114.bin
Creating Comm Object failed !
I've seen many different methods of resolving this problem. Most of them advising to create an udev rule like this:
echo 'SUBSYSTEM=="usb", ATTR{idVendor}=="2207", MODE="0666",GROUP="plugdev"' | sudo tee /etc/udev/rules.d/51-android.rules
None of them worked with 5.8.3 kernel. I suppose this problem is generally somehow connected to a newer kernels - 5.5 and up.
The actual the solution is very simple:
echo -1 > /sys/module/usbcore/parameters/autosuspend
That's it. Reconnect the device and you're ready to go. I suspect this problem applies to all devices with RK3399 SOC.