On Tue, 2012-03-27 at 16:41 +0200, Michal Kazior wrote: > Johannes Berg wrote: > > Ok, so ... I think we're getting to the bottom of our misunderstanding& > > confusion. I've completely ignored scan/off-channel in this because I > > don't have to handle it in software, our device handles it itself. It > > seems from this that you do need it handled in software. > > No, not really. I was just worried as to not break things and maybe > improve them as a bonus. Ah, ok. I agree we should be careful to not break things, but I don't think we should do more than we have to. In particular, I think adding multi-channel software implementation is too much :-) > > Now let's go back to the question of off-channel/scan -- this seems to > > be the fundamental difference in how we look at things. First, the same > > thing applies here. SW scanning in mac80211 right now is very > > inefficient when you try to do background scanning, since it doesn't > > synchronise with beacons etc. With multiple virtual interfaces, this > > will only get worse. With multiple channels, probably more so. > > > > Then also I'm in a bit of a luxurious position -- our device implements > > scanning and off-channel all by itself. For this reason, but also > > because of the timing, I've always wanted to ignore off-channel and > > scanning in the multi-channel code as much as possible. > > > > Your proposal to add temporary channel contexts might be feasible, but I > > wonder how complex it would become and how much of it can really be > > shared? I expect that ath9k will implement multi-channel completely in > > software, and any scheduler there would probably also roll in > > scanning/off-channel. (Not that I know, I don't work for QCA :) ) > > It would be nice if someone from Atheros camp could give us a hint on that. Yeah, though I'm not sure I care at this stage? I'm sure when (if?) they implement this they can come up with a proposal, and if it ends up being useful for somebody else at some point then they can work together to design the code to handle it all. > > Would that seem okay to you? I'd rather leave this complexity out of > > mac80211, not just for complexity reasons but also to make the API have > > easier semantics. > > I get the general idea but I can't imagine any detailed examples. I'm > yet to fully understand mac80211 and other drivers/devices. Ok. Basically I'm punting software-off-channel/-scan in multi-channel context -- is that something you could work with for your device? Does your device have hw-scan/hw-off-channel? johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
