Sorry about being much too late into this discussion. I'm not having the bandwidth to read netdev anymore, and just stumbled across this now.
Andrew Lunn <and...@lunn.ch> writes: > So, this is what all the Ethernet nonsense is all about. You have a > session ID you need to somehow represent to user space. And you > decided to use VLANs. But to use VLANs, you need an Ethernet > header. So you added a bogus Ethernet header. Actually, the original reasoning was the other way around. The bogus ethernet header was added because I had seen the 3G modem vendors do that for a few years already, in the modem firmware. And I didn't think enough about it to realize that it was a really bad idea, or even that it was something I could change. Or should change. I cannot blame the MBIM sesison to VLAN mapping idea on anyone else. As far as I can remember, that was just something that popped up in my head while working on the cdc_mbim driver. But it came as a consequence of already having the bogus ethernet header. And I didn't really understand that I could define a new wwan subsystem with new device types. I thought I had to use whatever was there already. I was young and stupid. Now I'm not that young anymore ;-) Never ever imagined that this would be replicated in another driver, though. That doesn't really make much sense. We have learned by now, haven't we? This subject has been discussed a few times in the past, and Johannes summary is my understanding as well: "I don't think anyone likes that" The DSS mapping sucks even more that the IPS mapping, BTW. I don't think there are any real users? Not that I know of, at least. DSS is much better implmeneted as some per-session character device, as requested by numerous people for years. Sorry for not listening. Looks like it is too late now. > Is any of this VLAN stuff required by MBIM? No. It's my fault and mine alone. > I suggest you throw away the pretence this is an Ethernet device. It > is not. I completely agree. I wish I had gone for simple raw-ip devices both in the qmi_wwan and cdc_mbim. But qmi_wwan got them later, so there is already support for such things in wwan userspace. Bjørn
