mac80211: wait for beacon before enabling powersave

Because DTIM information is required for powersave
but is only conveyed in beacons, wait for a beacon
before enabling powersave, and change the way the
information is conveyed to the driver accordingly.

mwl8k doesn't currently seem to implement PS but
requires the DTIM period in a different way; after
talking to Lennert we agreed to just have mwl8k do
the parsing itself in the finalize_join work.

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

1 files changed, 9 insertions, 5 deletions

diff --git a/drivers/net/wireless/mwl8k.c b/drivers/net/wireless/mwl8k.c
index 68546ca0ba37..f0f08f3919cc 100644
--- a/drivers/net/wireless/mwl8k.c
+++ b/drivers/net/wireless/mwl8k.c
@@ -3881,12 +3881,16 @@ static void mwl8k_finalize_join_worker(struct work_struct *work)
         struct mwl8k_priv *priv =
                 container_of(work, struct mwl8k_priv, finalize_join_worker);
         struct sk_buff *skb = priv->beacon_skb;
-        struct mwl8k_vif *mwl8k_vif;
+        struct ieee80211_mgmt *mgmt = (void *)skb->data;
+        int len = skb->len - offsetof(struct ieee80211_mgmt, u.beacon.variable);
+        const u8 *tim = cfg80211_find_ie(WLAN_EID_TIM,
+                                         mgmt->u.beacon.variable, len);
+        int dtim_period = 1;
+
+        if (tim && tim[1] >= 2)
+                dtim_period = tim[3];
 
-        mwl8k_vif = mwl8k_first_vif(priv);
-        if (mwl8k_vif != NULL)
-                mwl8k_cmd_finalize_join(priv->hw, skb->data, skb->len,
-                                        mwl8k_vif->vif->bss_conf.dtim_period);
+        mwl8k_cmd_finalize_join(priv->hw, skb->data, skb->len, dtim_period);
 
         dev_kfree_skb(skb);
         priv->beacon_skb = NULL;