Hello,
We’re having trouble with making the PLLAON clock persistent for CAN. We flashed the Jetpack 4.5.1 with the modified dtb files according to the documentation at How to enable PLLAON and also with a bit of help from this topic Update The device tree for can bus pllaon
Right after flashing we can enable CAN as expected and it has the right clock PLLAON at 50MHz. Then we run ‘apt update && apt upgrade’ to bring the packages up to date and after the reboot the CAN clock is set to OSC and there is no way to select it back to PLLAON.
From the current device tree it seems that pll_aon is still enabled, but there doesn’t seem to be a way to move the can under pll_aon:
osc 1 38400000 14 0
can1 1 38400000 3 1 vdd_aon@800000
can1_host 1 38400000 1 1 vdd_aon@800000
can1_core 1 38400000 1 1 vdd_aon@800000
can2 1 38400000 3 1 vdd_aon@800000
can2_host 1 38400000 1 1 vdd_aon@800000
can2_core 1 38400000 1 1 vdd_aon@800000
...
osc_div
...
pll_aon 1 400000000 2 0
Also, during the ‘apt upgrade’ procedure, the nvidia-l4t-kernel nvidia-l4t-kernel-dtbs nvidia-l4t-kernel-headers packages were updated, which we suspect is the root cause of this issue.
Is there a way to make the PLLAON clock persistent after upgrading system packages?