What:		/sys/class/net/<iface>/dsa/tagging
Date:		August 2018
KernelVersion:	4.20
Contact:	netdev@vger.kernel.org
Description:
		On read, this file returns a string indicating the type of
		tagging protocol used by the DSA network devices that are
		attached to this master interface.
		On write, this file changes the tagging protocol of the
		attached DSA switches, if this operation is supported by the
		driver. Changing the tagging protocol must be done with the DSA
		interfaces and the master interface all administratively down.
		See the "name" field of each registered struct dsa_device_ops
		for a list of valid values.