os883 - ethernet was automatically assigned to interface eth0

[mikus]

Was running an XO-1 (os883) with USB keyboard and USB-ethernet adapter plugged in. To test device assignmant, I deleted /etc/udev/rules.d/70-persistent-net.rules then rebooted (with USB-ethernet adpater still plugged in). When the system came up (into Sugar), the ethernet device had been assigned to interface 'eth0'. Took system dump.

[mikus]

os883 (XO1) - system dump when ethernet assigned to interface 'eth0'

[dsd]

Easily reproducible, and I can also hit another situation where the system hangs during boot as it tries to rename both the USB-ethernet and internal wifi to eth0 (unplugging the ethernet device allows the wifi to 'win' and boot to continue).

using udev's INTERFACE_NAME mechanism doesn't seem wholly appropriate here - only taking effect when hardware is present, but we want eth0 to be avoided by other devices even if the wifi card is not present internally on first boot. (plus it didn't seem to have much effect in my testing).

according to the current write_net_rules implementation, we can avoid this by putting the olpc NAME=eth0 rules in the (usually autogenerated) persistent-net.rules. the generator will see that an existing rule assigns something to eth0 and not use it for other automatic assignments.

we should ask about this on the hotplug list.

[dsd]

This got a bit simpler in F17 as the persistent net naming stuff got dropped.

Fixed in olpc-utils-2.0.5: we use udev rules to put the wifi device on eth0, and we use a udev naming script to apply a different name to anything else that the kernel wants to call eth0.

[pbrobinson]

should be fixed in os6, please test

[dsd]

I'm happy this is working, and as its outside of the normal use case in schools, no further QA is necessary.