On Tue, Dec 11, 2018 at 11:59:34PM +0000, tristram...@microchip.com wrote:
> > I'd be careful about locking. Seems like dsa was designed with "tag
> > format is static", and you want to change it dynamically...
>
> I see there is now a new overhead parameter in the dsa_device_ops structure
> and dev_set_mtu is called in master.c. It does not prevent the tag size to
> change dynamically though. A bigger size can be used instead to make sure the
> MAC controller can support it.
>
> In practice I do not think it does anything meaningful. Most MAC controllers
> can transmit and receive more than 1518 bytes but still only advertise 1500
> MTU.
Hi Tristram
There are a few MAC devices to do enforce 1518. e1000e is one
example. You have to increase the MTU before it will receive DSA
tagged frames. I initially had similar problems with the FEC driver
when i started using that a few years ago. At that time i did not
rallies it was a wide scale problem and just changed the FEC. This
should be a more generic solution.
Andrew
