bb-customizations: overlap between generic-board-startup and /etc/udev/rules.d/*gpio*.rules

[nahuel]

The /etc/udev/rules.d/*gpio*.rules files changes the owner/group of the gpio device files to root:gpio, but this is also done in /opt/scripts/boot/generic-startup.sh so there seems to be a redundancy here. Also a race condition between udev and generic-statup.sh will manifest if you add your own udev rules files to set the gpio device files owner/group to be run after the bb-customizations ones with another user/group, breaking what you expect from an udev based system. Probably it will be better to remove the chown's from generic-startup.sh

Besides this, I think the *.rules files must use RUN+= instead of PROGRAM= to call chown.

[turmary]

I have also a confusion about /etc/udev/rules.d/*gpio*.rules
They slow down the Debian system startup speed, take extra time more than a miniute.

[RobertCNelson]

@turmary do you have any hints/patches for speed up?

[turmary]

Yes, I have a patch which tested on PocketBeagle Linux v4.9.X.
Instead of travesing /sys/devices/platform/ocp/ocp:*pinmux by chown/chmod, it only traverse specific
/sys/devices/platform/ocp/ocp:XXX_pinmux path each time the udev rule executing.
etc_udev_rules_d.patch.txt

It will speed up the startup one minute time approximately.

I also noticed that keywords OWNER/GROUP/MODE in rules file doesn't take effect.

[amilcarlucas]

@turmary can you do a github pull request against current master?

[RobertCNelson]

@amilcarlucas gpio permissions are no longer done in generic-startup.sh, it should all be taken by the udev rules:

https://github.com/beagleboard/customizations/tree/master/etc/udev/rules.d

Regards,