mac80211: Enhancements to dynamic power save.

This patch enables mac80211 to send a null frame and also to
check for tim in the beacon if dynamic power save is enabled.

Signed-off-by: Vivek Natarajan <vnatarajan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

4 files changed, 53 insertions, 6 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 5f8ad885a48a..117718bd96ec 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -987,6 +987,9 @@ u64 ieee80211_mandatory_rates(struct ieee80211_local *local,
 void ieee80211_dynamic_ps_enable_work(struct work_struct *work);
 void ieee80211_dynamic_ps_disable_work(struct work_struct *work);
 void ieee80211_dynamic_ps_timer(unsigned long data);
+void ieee80211_send_nullfunc(struct ieee80211_local *local,
+                             struct ieee80211_sub_if_data *sdata,
+                             int powersave);
 
 void ieee80211_wake_queues_by_reason(struct ieee80211_hw *hw,
                                      enum queue_stop_reason reason);
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index b3c99d3c61ba..599a42172a16 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -575,6 +575,30 @@ static void ieee80211_sta_wmm_params(struct ieee80211_local *local,
         }
 }
 
+static bool check_tim(struct ieee802_11_elems *elems, u16 aid, bool *is_mc)
+{
+        u8 mask;
+        u8 index, indexn1, indexn2;
+        struct ieee80211_tim_ie *tim = (struct ieee80211_tim_ie *) elems->tim;
+
+        aid &= 0x3fff;
+        index = aid / 8;
+        mask  = 1 << (aid & 7);
+
+        if (tim->bitmap_ctrl & 0x01)
+                *is_mc = true;
+
+        indexn1 = tim->bitmap_ctrl & 0xfe;
+        indexn2 = elems->tim_len + indexn1 - 4;
+
+        if (index < indexn1 || index > indexn2)
+                return false;
+
+        index -= indexn1;
+
+        return !!(tim->virtual_map[index] & mask);
+}
+
 static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
                                            u16 capab, bool erp_valid, u8 erp)
 {
@@ -757,6 +781,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
                         mod_timer(&local->dynamic_ps_timer, jiffies +
                                   msecs_to_jiffies(local->dynamic_ps_timeout));
                 else {
+                        ieee80211_send_nullfunc(local, sdata, 1);
                         conf->flags |= IEEE80211_CONF_PS;
                         ieee80211_hw_config(local,
                                             IEEE80211_CONF_CHANGE_PS);
@@ -1720,7 +1745,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
         struct ieee802_11_elems elems;
         struct ieee80211_local *local = sdata->local;
         u32 changed = 0;
-        bool erp_valid;
+        bool erp_valid, directed_tim, is_mc = false;
         u8 erp_value = 0;
 
         /* Process beacon from the current BSS */
@@ -1743,6 +1768,18 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata,
         ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
                                  elems.wmm_param_len);
 
+        if (!(local->hw.flags & IEEE80211_HW_NO_STACK_DYNAMIC_PS)) {
+                directed_tim = check_tim(&elems, ifsta->aid, &is_mc);
+
+                if (directed_tim || is_mc) {
+                        if (local->hw.conf.flags && IEEE80211_CONF_PS) {
+                                local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+                                ieee80211_hw_config(local,
+                                                IEEE80211_CONF_CHANGE_PS);
+                                ieee80211_send_nullfunc(local, sdata, 0);
+                        }
+                }
+        }
 
         if (elems.erp_info && elems.erp_info_len >= 1) {
                 erp_valid = true;
@@ -2631,10 +2668,12 @@ void ieee80211_dynamic_ps_enable_work(struct work_struct *work)
         struct ieee80211_local *local =
                 container_of(work, struct ieee80211_local,
                              dynamic_ps_enable_work);
+        struct ieee80211_sub_if_data *sdata = local->scan_sdata;
 
         if (local->hw.conf.flags & IEEE80211_CONF_PS)
                 return;
 
+        ieee80211_send_nullfunc(local, sdata, 1);
         local->hw.conf.flags |= IEEE80211_CONF_PS;
 
         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index f5c7c3371929..a2caeed57f4e 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -395,7 +395,7 @@ ieee80211_scan_rx(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb,
         return RX_QUEUED;
 }
 
-static void ieee80211_send_nullfunc(struct ieee80211_local *local,
+void ieee80211_send_nullfunc(struct ieee80211_local *local,
                                     struct ieee80211_sub_if_data *sdata,
                                     int powersave)
 {
diff --git a/net/mac80211/wext.c b/net/mac80211/wext.c
index 8568f1e7266f..48fc6b9a62a4 100644
--- a/net/mac80211/wext.c
+++ b/net/mac80211/wext.c
@@ -871,12 +871,17 @@ set:
                         mod_timer(&local->dynamic_ps_timer, jiffies +
                                   msecs_to_jiffies(local->dynamic_ps_timeout));
                 else {
-                        if (local->powersave)
+                        if (local->powersave) {
+                                ieee80211_send_nullfunc(local, sdata, 1);
                                 conf->flags |= IEEE80211_CONF_PS;
-                        else
+                                ret = ieee80211_hw_config(local,
+                                                IEEE80211_CONF_CHANGE_PS);
+                        } else {
                                 conf->flags &= ~IEEE80211_CONF_PS;
-                        ret = ieee80211_hw_config(local,
-                                        IEEE80211_CONF_CHANGE_PS);
+                                ret = ieee80211_hw_config(local,
+                                                IEEE80211_CONF_CHANGE_PS);
+                                ieee80211_send_nullfunc(local, sdata, 0);
+                        }
                 }
         }