On 2011-02-14 1:09 PM, Johannes Berg wrote: > On Wed, 2011-02-09 at 00:32 +0100, Felix Fietkau wrote: >> When a driver wants to buffer some frames internally without feeding them >> back to mac80211, this allows it to still wake up the station > > Why would the driver want to do this though? If a station enters powersave and the AP still has buffered frames for aggregation, those frames need to stay in the queue, since the driver controls the block ack window and keeps some state per frame (e.g. number of software retransmissions). If ath9k would send those frames back to mac80211, and mac80211 would drop some of them, then the client's reorder window would get messed up when the client comes back. This would also make managing frame sequence numbers more complicated, since the driver would have to skip assigning sequence numbers for frames where tx_info->flags has the IEEE80211_TX_INTFL_RETRANSMISSION bit set, but then also look for gaps caused by expired frames. - Felix -- 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
