Messages in this thread | | | Subject | Re: [PATCH net-next 16/17] Documentation: networking: dsa: Add details about NXP SJA1105 driver | From | Florian Fainelli <> | Date | Wed, 3 Apr 2019 08:07:24 -0700 |
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On 4/3/2019 3:09 AM, Vladimir Oltean wrote: > On 4/3/19 12:24 AM, Andrew Lunn wrote: >>> +The switches do not support switch tagging in hardware. But they do >>> support >>> +customizing the TPID by which VLAN traffic is identified as such. >>> The switch >>> +driver is leveraging CONFIG_NET_DSA_TAG_8021Q by requesting that >>> special VLANs >>> +(with a custom TPID of ETH_P_EDSA instead of ETH_P_8021Q) >> >> Hi Vladimir >> >> Reusing ETH_P_EDSA is possibility going to case problems in tcpdump. >> It has code which looks for this Ethertype and uses it to call the >> Marvell EDSA header decoder code. This is not going to work for your >> switch, where you have a normal VLAN header. >> >> I wounder if we should allocate a new EtherType for this application >> of VLANs? >> >> Andrew >> > > Hi Andrew, > > This makes me wonder whether I would be able to use an EtherType range > to support cascading switch tags on SJA1105. > In theory if I were to consistently lie to all switches within a switch > tree, I could make all of them see each other's fake VLAN-tagged traffic > as untagged. > By the way what is the simple ETH_P_DSA used for?
ETH_P_DSA is not used since commit 3e8a72d1dae374cf6fc1dba97cec663585845ff9 ("net: dsa: reduce number of protocol hooks") but since it is in an UAPI exported file we probably cannot remove it. -- Florian
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