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, 16 insertions, 9 deletions

diff --git a/net/mac80211/debugfs_netdev.c b/net/mac80211/debugfs_netdev.c
index cafe614ef93d..04b5a14c8a05 100644
--- a/net/mac80211/debugfs_netdev.c
+++ b/net/mac80211/debugfs_netdev.c
@@ -224,12 +224,15 @@ static int ieee80211_set_smps(struct ieee80211_sub_if_data *sdata,
              smps_mode == IEEE80211_SMPS_AUTOMATIC))
                 return -EINVAL;
 
-        /* supported only on managed interfaces for now */
-        if (sdata->vif.type != NL80211_IFTYPE_STATION)
+        if (sdata->vif.type != NL80211_IFTYPE_STATION &&
+            sdata->vif.type != NL80211_IFTYPE_AP)
                 return -EOPNOTSUPP;
 
         sdata_lock(sdata);
-        err = __ieee80211_request_smps(sdata, smps_mode);
+        if (sdata->vif.type == NL80211_IFTYPE_STATION)
+                err = __ieee80211_request_smps_mgd(sdata, smps_mode);
+        else
+                err = __ieee80211_request_smps_ap(sdata, smps_mode);
         sdata_unlock(sdata);
 
         return err;
@@ -245,12 +248,15 @@ static const char *smps_modes[IEEE80211_SMPS_NUM_MODES] = {
 static ssize_t ieee80211_if_fmt_smps(const struct ieee80211_sub_if_data *sdata,
                                      char *buf, int buflen)
 {
-        if (sdata->vif.type != NL80211_IFTYPE_STATION)
-                return -EOPNOTSUPP;
-
-        return snprintf(buf, buflen, "request: %s\nused: %s\n",
-                        smps_modes[sdata->u.mgd.req_smps],
-                        smps_modes[sdata->smps_mode]);
+        if (sdata->vif.type == NL80211_IFTYPE_STATION)
+                return snprintf(buf, buflen, "request: %s\nused: %s\n",
+                                smps_modes[sdata->u.mgd.req_smps],
+                                smps_modes[sdata->smps_mode]);
+        if (sdata->vif.type == NL80211_IFTYPE_AP)
+                return snprintf(buf, buflen, "request: %s\nused: %s\n",
+                                smps_modes[sdata->u.ap.req_smps],
+                                smps_modes[sdata->smps_mode]);
+        return -EINVAL;
 }
 
 static ssize_t ieee80211_if_parse_smps(struct ieee80211_sub_if_data *sdata,
@@ -563,6 +569,7 @@ static void add_sta_files(struct ieee80211_sub_if_data *sdata)
 static void add_ap_files(struct ieee80211_sub_if_data *sdata)
 {
         DEBUGFS_ADD(num_mcast_sta);
+        DEBUGFS_ADD_MODE(smps, 0600);
         DEBUGFS_ADD(num_sta_ps);
         DEBUGFS_ADD(dtim_count);
         DEBUGFS_ADD(num_buffered_multicast);