mac80211: implement SMPS for AP

When the driver requests to move to STATIC or DYNAMIC SMPS,
we send an action frame to each associated station and
reconfigure the channel context / driver.
Of course, non-MIMO stations are ignored.

The beacon isn't updated. The association response will
include the original capabilities. Stations that associate
while in non-OFF SMPS mode will get an action frame right
after association to inform them about our current state.
Note that we wait until the end of the EAPOL. Sending an
action frame before the EAPOL is finished can be an issue
for a few clients. Clients aren't likely to send EAPOL
frames in MIMO anyway.

When the SMPS configuration gets more permissive (e.g.
STATIC -> OFF), we don't wake up stations that are asleep
We remember that they don't know about the change and send
the action frame when they wake up.

When the SMPS configuration gets more restrictive (e.g.
OFF -> STATIC), we set the TIM bit for every sleeping STA.
uAPSD stations might send MIMO until they poll the action
frame, but this is for a short period of time.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[fix vht streams loop, initialisation]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 4208dbd5861..3ef06a26b9c 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -301,6 +301,8 @@ struct sta_ampdu_mlme {
  * @chains: chains ever used for RX from this station
  * @chain_signal_last: last signal (per chain)
  * @chain_signal_avg: signal average (per chain)
+ * @known_smps_mode: the smps_mode the client thinks we are in. Relevant for
+ *	AP only.
  */
 struct sta_info {
 	/* General information, mostly static */
@@ -411,6 +413,8 @@ struct sta_info {
 	unsigned int lost_packets;
 	unsigned int beacon_loss_count;
 
+	enum ieee80211_smps_mode known_smps_mode;
+
 	/* keep last! */
 	struct ieee80211_sta sta;
 };
@@ -613,6 +617,7 @@ void sta_set_rate_info_rx(struct sta_info *sta,
 			  struct rate_info *rinfo);
 void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
 			  unsigned long exp_time);
+u8 sta_info_tx_streams(struct sta_info *sta);
 
 void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta);
 void ieee80211_sta_ps_deliver_poll_response(struct sta_info *sta);