Hello,
....
Also, please note, the kernel does not guarantee that the ttyUSB and
ttyAMA ports are always named in the same way, so using udev rules
like that is error-prone. A much better approach would be to bind the
udev rules to specific sysfs paths, e.g.
DEVPATH=="/devices/pci0000:00/0000:00:1d.0/usb4/4-1/4-1.5/4-1.5.5"
Only a note:
I have noticed that the path is no longer fixed with newer kernels.
The problem is the `usb<port-number>` in your example `usb4`. This is
random and can be different for each boot, since probing of the usb
root hubs are now done asynchronous during but. I have noticed this,
on my APU3 board which is running the kernel version 6.6.xxx
(owrt-24.10).
Also, the ACTION rule is missing "bind". The udev tags must be set in
all "add", "change" and "bind" actions. This may actually be your
issue.
Best regards
Florian
