Missing tty device of_node info after 6.8-rc1

[Aidan Stewart]

Hello,

After upgrading from the 6.6 stable kernel series to the 6.12 series, I can no
longer see any of_node information under /sys/class/tty/ttySn/device/of_node/.
This breaks a few of my udev rules for creating symlinks in /dev for these
devices.

This is still present in 6.16-rc1. I have checked on the following hardware:

 * Our custom AM335x board
 * Beagle Black (AM335x)
 * Texas Instruments TMDS62LEVM

and the of_node information is missing from all of these in 6.12. I bisected the issue
to the following commit [1] in 6.8-rc1:

commit b286f4e87e325b76789f30337c98ba72e00532e2
Author: Tony Lindgren <tony@xxxxxxxxxxx>
Date:   Mon Nov 13 10:07:52 2023 +0200

    serial: core: Move tty and serdev to be children of serial core port device

Possibly related, this change also seems to have caused issues with another
driver [2].

Is there any way to view the of_node information (perhaps a KConfig option?), or
is it simply no longer available?

Any assistance would be greatly appreciated.

Thanks,

Aidan Stewart

[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.16-rc1&id=b286f4e87e325b76789f30337c98ba72e00532e2
[2] https://lore.kernel.org/netdev/20240829183603.1156671-1-vadfed@xxxxxxxx/