mac80211: enable spatial multiplexing powersave

Enable spatial multiplexing in mac80211 by telling the
driver what to do and, where necessary, sending action
frames to the AP to update the requested SMPS mode.

Also includes a trivial implementation for hwsim that
just logs the requested mode.

For now, the userspace interface is in debugfs only,
and let you toggle the requested mode at any time.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index fcfa1bf776a..8c35418d1c9 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1318,6 +1318,50 @@ static int ieee80211_testmode_cmd(struct wiphy *wiphy, void *data, int len)
 }
 #endif
 
+int __ieee80211_request_smps(struct ieee80211_sub_if_data *sdata,
+                             enum ieee80211_smps_mode smps_mode)
+{
+        const u8 *ap;
+        enum ieee80211_smps_mode old_req;
+        int err;
+
+        old_req = sdata->u.mgd.req_smps;
+        sdata->u.mgd.req_smps = smps_mode;
+
+        if (old_req == smps_mode &&
+            smps_mode != IEEE80211_SMPS_AUTOMATIC)
+                return 0;
+
+        /*
+         * If not associated, or current association is not an HT
+         * association, there's no need to send an action frame.
+         */
+        if (!sdata->u.mgd.associated ||
+            sdata->local->oper_channel_type == NL80211_CHAN_NO_HT) {
+                mutex_lock(&sdata->local->iflist_mtx);
+                ieee80211_recalc_smps(sdata->local, sdata);
+                mutex_unlock(&sdata->local->iflist_mtx);
+                return 0;
+        }
+
+        ap = sdata->u.mgd.associated->cbss.bssid;
+
+        if (smps_mode == IEEE80211_SMPS_AUTOMATIC) {
+                if (sdata->u.mgd.powersave)
+                        smps_mode = IEEE80211_SMPS_DYNAMIC;
+                else
+                        smps_mode = IEEE80211_SMPS_OFF;
+        }
+
+        /* send SM PS frame to AP */
+        err = ieee80211_send_smps_action(sdata, smps_mode,
+                                         ap, ap);
+        if (err)
+                sdata->u.mgd.req_smps = old_req;
+
+        return err;
+}
+
 static int ieee80211_set_power_mgmt(struct wiphy *wiphy, struct net_device *dev,
                                     bool enabled, int timeout)
 {
@@ -1335,6 +1379,11 @@ static int ieee80211_set_power_mgmt(struct wiphy *wiphy, struct net_device *dev,
         sdata->u.mgd.powersave = enabled;
         conf->dynamic_ps_timeout = timeout;
 
+        /* no change, but if automatic follow powersave */
+        mutex_lock(&sdata->u.mgd.mtx);
+        __ieee80211_request_smps(sdata, sdata->u.mgd.req_smps);
+        mutex_unlock(&sdata->u.mgd.mtx);
+
         if (local->hw.flags & IEEE80211_HW_SUPPORTS_DYNAMIC_PS)
                 ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);