mac80211: document TX powersave filter requirements

This documents what's required to implement that TX powersave
filter properly wrt. handling hardware queues.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg 2009-08-07 16:28:09 +02:00 committed by John W. Linville
parent c555b9b371
commit ab5b5342fd

View file

@ -239,7 +239,14 @@ struct ieee80211_bss_conf {
* @IEEE80211_TX_CTL_AMPDU: this frame should be sent as part of an A-MPDU
* @IEEE80211_TX_CTL_INJECTED: Frame was injected, internal to mac80211.
* @IEEE80211_TX_STAT_TX_FILTERED: The frame was not transmitted
* because the destination STA was in powersave mode.
* because the destination STA was in powersave mode. Note that to
* avoid race conditions, the filter must be set by the hardware or
* firmware upon receiving a frame that indicates that the station
* went to sleep (must be done on device to filter frames already on
* the queue) and may only be unset after mac80211 gives the OK for
* that by setting the IEEE80211_TX_CTL_CLEAR_PS_FILT (see above),
* since only then is it guaranteed that no more frames are in the
* hardware queue.
* @IEEE80211_TX_STAT_ACK: Frame was acknowledged
* @IEEE80211_TX_STAT_AMPDU: The frame was aggregated, so status
* is for the whole aggregation.