Re: RFC: dsa slave open handling

quoted

quoted

quoted

quoted

"Lennert" == Lennert Buytenhek [off-list ref] writes:

Hi,

 >> Currently the state of the dsa master device and slave devices are not
 >> synchronized which leads to various issues. With dsa, the master device
 >> needs to be running before you can use the slave devices, but it
 >> shouldn't be used directly for I/O.

 Lennert> I think this should not be handled any differently than VLAN
 Lennert> interfaces, where eth0 needs to be up before you can exchange
 Lennert> packets over eth0.123.

 Lennert> IOW, if you want to do DHCP over wan (a DSA-tunneled interface
 Lennert> over eth0), then just use an initramfs that sets eth0 up and
 Lennert> then runs a DHCP client on wan.

True. There are a few differences between vlans and dsa devices though,
which might make us want to handle them differently:

- VLANs are configured at runtime from userspace, DSA devices are
  configured directly in kernel code (E.G platform devices) - So by
  definition you cannot use the autconfig / nfsroot stuff on VLANs as
  they are not created before userspace runs, but DSA devices are
  basically indistinguishable from "real" devices from the POV of
  userspace.

- VLANs relation to their upstream ethernet device is clearly visible
  (E.G through brctl), whereas the details about what interface a DSA
  switch is connected to isn't.

-- 
Bye, Peter Korsgaard