From: Johannes Berg <johannes.berg@xxxxxxxxx> Even before the recent changes, the documentation for TX aggregation was somewhat out of date. Update it and also add documentation for the RX side. Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> --- net/mac80211/agg-rx.c | 23 +++++++++++++++++++++++ net/mac80211/agg-tx.c | 43 +++++++++++++++++++++++++++---------------- 2 files changed, 50 insertions(+), 16 deletions(-) --- wireless-testing.orig/net/mac80211/agg-tx.c 2010-06-09 17:21:17.000000000 +0200 +++ wireless-testing/net/mac80211/agg-tx.c 2010-06-09 17:21:18.000000000 +0200 @@ -21,28 +21,39 @@ #include "wme.h" /** - * DOC: TX aggregation + * DOC: TX A-MPDU aggregation * * Aggregation on the TX side requires setting the hardware flag - * %IEEE80211_HW_AMPDU_AGGREGATION as well as, if present, the @ampdu_queues - * hardware parameter to the number of hardware AMPDU queues. If there are no - * hardware queues then the driver will (currently) have to do all frame - * buffering. + * %IEEE80211_HW_AMPDU_AGGREGATION. The driver will then be handed + * packets with a flag indicating A-MPDU aggregation. The driver + * or device is responsible for actually aggregating the frames, + * as well as deciding how many and which to aggregate. * - * When TX aggregation is started by some subsystem (usually the rate control - * algorithm would be appropriate) by calling the - * ieee80211_start_tx_ba_session() function, the driver will be notified via - * its @ampdu_action function, with the %IEEE80211_AMPDU_TX_START action. + * When TX aggregation is started by some subsystem (usually the rate + * control algorithm would be appropriate) by calling the + * ieee80211_start_tx_ba_session() function, the driver will be + * notified via its @ampdu_action function, with the + * %IEEE80211_AMPDU_TX_START action. * * In response to that, the driver is later required to call the - * ieee80211_start_tx_ba_cb() (or ieee80211_start_tx_ba_cb_irqsafe()) - * function, which will start the aggregation session. + * ieee80211_start_tx_ba_cb_irqsafe() function, which will really + * start the aggregation session after the peer has also responded. + * If the peer responds negatively, the session will be stopped + * again right away. Note that it is possible for the aggregation + * session to be stopped before the driver has indicated that it + * is done setting it up, in which case it must not indicate the + * setup completion. * - * Similarly, when the aggregation session is stopped by - * ieee80211_stop_tx_ba_session(), the driver's @ampdu_action function will - * be called with the action %IEEE80211_AMPDU_TX_STOP. In this case, the - * call must not fail, and the driver must later call ieee80211_stop_tx_ba_cb() - * (or ieee80211_stop_tx_ba_cb_irqsafe()). + * Also note that, since we also need to wait for a response from + * the peer, the driver is notified of the completion of the + * handshake by the %IEEE80211_AMPDU_TX_OPERATIONAL action to the + * @ampdu_action callback. + * + * Similarly, when the aggregation session is stopped by the peer + * or something calling ieee80211_stop_tx_ba_session(), the driver's + * @ampdu_action function will be called with the action + * %IEEE80211_AMPDU_TX_STOP. In this case, the call must not fail, + * and the driver must later call ieee80211_stop_tx_ba_cb_irqsafe(). */ static void ieee80211_send_addba_request(struct ieee80211_sub_if_data *sdata, --- wireless-testing.orig/net/mac80211/agg-rx.c 2010-06-09 17:21:16.000000000 +0200 +++ wireless-testing/net/mac80211/agg-rx.c 2010-06-09 17:21:18.000000000 +0200 @@ -13,6 +13,29 @@ * published by the Free Software Foundation. */ +/** + * DOC: RX A-MPDU aggregation + * + * Aggregation on the RX side requires only implementing the + * @ampdu_action callback that is invoked to start/stop any + * block-ack sessions for RX aggregation. + * + * When RX aggregation is started by the peer, the driver is + * notified via @ampdu_action function, with the + * %IEEE80211_AMPDU_RX_START action, and may reject the request + * in which case a negative response is sent to the peer, if it + * accepts it a positive response is sent. + * + * While the session is active, the device/driver are required + * to de-aggregate frames and pass them up one by one to mac80211, + * which will handle the reorder buffer. + * + * When the aggregation session is stopped again by the peer or + * ourselves, the driver's @ampdu_action function will be called + * with the action %IEEE80211_AMPDU_RX_STOP. In this case, the + * call must not fail. + */ + #include <linux/ieee80211.h> #include <linux/slab.h> #include <net/mac80211.h> -- 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
