Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes: > On Sun, 2008-10-19 at 14:00 +0300, Kalle Valo wrote: > >> > Then add a new flag to mac80211 hw description that says "driver will >> > watch beacons". This means that the code above that rearms the timer for >> > the future 'nothing from AP' check is skipped. >> >> I will. I need to check that if the "firmware beacon watch" is enabled >> only when PSM is enabled. If it is, we might have to make the flag >> dynamic. > > IIRC it's a separate flag. Very good, that would be the best way. >> There isn't any >> timeout for delivering beacons to the host, if the data path is idle >> for 24 hours, mac80211 will not receive any beacons for the 24 hours. >> I don't see why we need a timeout here. > > Right. But we need to program the chip to tell the chip "hey please tell > me if you haven't seen a beacon in X seconds". Ah, you mean that timeout. Sorry, I forgot that one altogether. Yes, we definitely need that timeout. >> I believe that there's also a feature in stlc4560 that the driver can >> provide a checksum of the beacon and the firmware will send the beacon >> if checksum doesn't match. But I don't yet know how that works in >> practise. > > It seems to be a firmware feature, first beacon from the BSS the > firmware computes the checksum, and if it changes it lets the beacon go > through and re-computes the checksum, so you see all beacon changes. So the driver doesn't have to compute any checksums itself? That makes things easy then. > Maybe it excludes the TIM. It should. Otherwise beacon filtering in a crowded network with clients in PSM would be next to useless. And I didn't see any major increase in power consumption at Maemo Summit :) > I think we want this for when the QoS parameters or something else > changes. Yeah. Just out of curiosity, are there any other parameters which mac80211 needs to follow? Short preamble? Short slot time? Anything else? -- Kalle Valo -- 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
