On Tue, 2015-02-24 at 11:24 +0100, Johannes Berg wrote: > On Thu, 2015-02-12 at 08:48 +0100, Michal Kazior wrote: > > > > Good point. I was actually thinking about it. I can try cooking a > > > patch unless you want to do it yourself :-) > > > > I've taken a look into this. The most obvious place to add the > > timestamp for each packet would be ieee80211_tx_info (i.e. the > > skb->cb[48]). The problem is it's very tight there. Even squeezing 2 > > bytes (allowing up to 64ms of tx completion delay which I'm worried > > won't be enough) will be troublesome. Some drivers already use every > > last byte of their allowance on 64bit archs (e.g. ar5523 uses entire > > 40 bytes of driver_data). > > Couldn't we just repurpose the existing skb->tstamp field for this, as > long as the skb is fully contained within the wireless layer? > > Actually, it looks like we can't, since I guess timestamping options can > be turned on on any socket. Actually, that creates a clone or a new skb? Hmm. Anyway, I think we should just move the vif and hw_key pointers out of the tx_info and into ieee80211_tx_control. That will give us plenty of space, and they can't really be used long-term anyway? Although ... both might be somewhat problematic for mac80211 itself? Hmm. 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
