1 files changed, 88 insertions, 0 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 7776d9f1f297..2eb5196977fd 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -141,6 +141,16 @@ static void rt2x00lib_intf_scheduled(struct work_struct *work)
                                             rt2x00dev);
 }
 
+static void rt2x00lib_autowakeup(struct work_struct *work)
+{
+        struct rt2x00_dev *rt2x00dev =
+            container_of(work, struct rt2x00_dev, autowakeup_work.work);
+
+        if (rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_AWAKE))
+                ERROR(rt2x00dev, "Device failed to wakeup.\n");
+        clear_bit(CONFIG_POWERSAVING, &rt2x00dev->flags);
+}
+
 /*
  * Interrupt context handlers.
  */
@@ -416,6 +426,77 @@ void rt2x00lib_txdone_noinfo(struct queue_entry *entry, u32 status)
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_txdone_noinfo);
 
+static u8 *rt2x00lib_find_ie(u8 *data, unsigned int len, u8 ie)
+{
+        struct ieee80211_mgmt *mgmt = (void *)data;
+        u8 *pos, *end;
+
+        pos = (u8 *)mgmt->u.beacon.variable;
+        end = data + len;
+        while (pos < end) {
+                if (pos + 2 + pos[1] > end)
+                        return NULL;
+
+                if (pos[0] == ie)
+                        return pos;
+
+                pos += 2 + pos[1];
+        }
+
+        return NULL;
+}
+
+static void rt2x00lib_rxdone_check_ps(struct rt2x00_dev *rt2x00dev,
+                                      struct sk_buff *skb,
+                                      struct rxdone_entry_desc *rxdesc)
+{
+        struct ieee80211_hdr *hdr = (void *) skb->data;
+        struct ieee80211_tim_ie *tim_ie;
+        u8 *tim;
+        u8 tim_len;
+        bool cam;
+
+        /* If this is not a beacon, or if mac80211 has no powersaving
+         * configured, or if the device is already in powersaving mode
+         * we can exit now. */
+        if (likely(!ieee80211_is_beacon(hdr->frame_control) ||
+                   !(rt2x00dev->hw->conf.flags & IEEE80211_CONF_PS)))
+                return;
+
+        /* min. beacon length + FCS_LEN */
+        if (skb->len <= 40 + FCS_LEN)
+                return;
+
+        /* and only beacons from the associated BSSID, please */
+        if (!(rxdesc->dev_flags & RXDONE_MY_BSS) ||
+            !rt2x00dev->aid)
+                return;
+
+        rt2x00dev->last_beacon = jiffies;
+
+        tim = rt2x00lib_find_ie(skb->data, skb->len - FCS_LEN, WLAN_EID_TIM);
+        if (!tim)
+                return;
+
+        if (tim[1] < sizeof(*tim_ie))
+                return;
+
+        tim_len = tim[1];
+        tim_ie = (struct ieee80211_tim_ie *) &tim[2];
+
+        /* Check whenever the PHY can be turned off again. */
+
+        /* 1. What about buffered unicast traffic for our AID? */
+        cam = ieee80211_check_tim(tim_ie, tim_len, rt2x00dev->aid);
+
+        /* 2. Maybe the AP wants to send multicast/broadcast data? */
+        cam |= (tim_ie->bitmap_ctrl & 0x01);
+
+        if (!cam && !test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags))
+                rt2x00lib_config(rt2x00dev, &rt2x00dev->hw->conf,
+                                 IEEE80211_CONF_CHANGE_PS);
+}
+
 static int rt2x00lib_rxdone_read_signal(struct rt2x00_dev *rt2x00dev,
                                         struct rxdone_entry_desc *rxdesc)
 {
@@ -531,6 +612,12 @@ void rt2x00lib_rxdone(struct queue_entry *entry)
                 rxdesc.flags |= RX_FLAG_HT;
 
         /*
+         * Check if this is a beacon, and more frames have been
+         * buffered while we were in powersaving mode.
+         */
+        rt2x00lib_rxdone_check_ps(rt2x00dev, entry->skb, &rxdesc);
+
+        /*
          * Update extra components
          */
         rt2x00link_update_stats(rt2x00dev, entry->skb, &rxdesc);
@@ -1017,6 +1104,7 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
         }
 
         INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
+        INIT_DELAYED_WORK(&rt2x00dev->autowakeup_work, rt2x00lib_autowakeup);
 
         /*
          * Let the driver probe the device to detect the capabilities.