mac80211: implement off-channel TX using hw r-o-c offload

When the driver has remain-on-channel offload,
implement off-channel transmission using that
primitive.

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

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 168a6ba..4bc8a92 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1641,6 +1641,7 @@ static int ieee80211_remain_on_channel(struct wiphy *wiphy,
                ret = ieee80211_remain_on_channel_hw(local, dev,
                                                     chan, channel_type,
                                                     duration, cookie);
+               local->hw_roc_for_tx = false;
                mutex_unlock(&local->mtx);
 
                return ret;
@@ -1783,6 +1784,49 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct net_device *dev,
 
        *cookie = (unsigned long) skb;
 
+       if (is_offchan && local->ops->remain_on_channel) {
+               unsigned int duration;
+               int ret;
+
+               mutex_lock(&local->mtx);
+               /*
+                * If the duration is zero, then the driver
+                * wouldn't actually do anything. Set it to
+                * 100 for now.
+                *
+                * TODO: cancel the off-channel operation
+                *       when we get the SKB's TX status and
+                *       the wait time was zero before.
+                */
+               duration = 100;
+               if (wait)
+                       duration = wait;
+               ret = ieee80211_remain_on_channel_hw(local, dev, chan,
+                                                    channel_type,
+                                                    duration, cookie);
+               if (ret) {
+                       kfree_skb(skb);
+                       mutex_unlock(&local->mtx);
+                       return ret;
+               }
+
+               local->hw_roc_for_tx = true;
+               local->hw_roc_duration = wait;
+
+               /*
+                * queue up frame for transmission after
+                * ieee80211_ready_on_channel call
+                */
+
+               /* modify cookie to prevent API mismatches */
+               *cookie ^= 2;
+               IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_TX_OFFCHAN;
+               local->hw_roc_skb = skb;
+               mutex_unlock(&local->mtx);
+
+               return 0;
+       }
+
        /*
         * Can transmit right away if the channel was the
         * right one and there's no wait involved... If a
@@ -1823,6 +1867,21 @@ static int ieee80211_mgmt_tx_cancel_wait(struct wiphy *wiphy,
        int ret = -ENOENT;
 
        mutex_lock(&local->mtx);
+
+       if (local->ops->cancel_remain_on_channel) {
+               cookie ^= 2;
+               ret = ieee80211_cancel_remain_on_channel_hw(local, cookie);
+
+               if (ret == 0) {
+                       kfree_skb(local->hw_roc_skb);
+                       local->hw_roc_skb = NULL;
+               }
+
+               mutex_unlock(&local->mtx);
+
+               return ret;
+       }
+
        list_for_each_entry(wk, &local->work_list, list) {
                if (wk->sdata != sdata)
                        continue;

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index f866af8..c47d7c0 100644 (file)
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -953,10 +953,12 @@ struct ieee80211_local {
 
        struct ieee80211_channel *hw_roc_channel;
        struct net_device *hw_roc_dev;
+       struct sk_buff *hw_roc_skb;
        struct work_struct hw_roc_start, hw_roc_done;
        enum nl80211_channel_type hw_roc_channel_type;
        unsigned int hw_roc_duration;
        u32 hw_roc_cookie;
+       bool hw_roc_for_tx;
 
        /* dummy netdev for use w/ NAPI */
        struct net_device napi_dev;

diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 49b9ec2..b4e5267 100644 (file)
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -196,6 +196,7 @@ static void ieee80211_hw_roc_start(struct work_struct *work)
 {
        struct ieee80211_local *local =
                container_of(work, struct ieee80211_local, hw_roc_start);
+       struct ieee80211_sub_if_data *sdata;
 
        mutex_lock(&local->mtx);
 
@@ -206,11 +207,19 @@ static void ieee80211_hw_roc_start(struct work_struct *work)
 
        ieee80211_recalc_idle(local);
 
-       cfg80211_ready_on_channel(local->hw_roc_dev, local->hw_roc_cookie,
-                                 local->hw_roc_channel,
-                                 local->hw_roc_channel_type,
-                                 local->hw_roc_duration,
-                                 GFP_KERNEL);
+       if (local->hw_roc_skb) {
+               sdata = IEEE80211_DEV_TO_SUB_IF(local->hw_roc_dev);
+               ieee80211_tx_skb(sdata, local->hw_roc_skb);
+               local->hw_roc_skb = NULL;
+       } else {
+               cfg80211_ready_on_channel(local->hw_roc_dev,
+                                         local->hw_roc_cookie,
+                                         local->hw_roc_channel,
+                                         local->hw_roc_channel_type,
+                                         local->hw_roc_duration,
+                                         GFP_KERNEL);
+       }
+
        mutex_unlock(&local->mtx);
 }
 
@@ -236,11 +245,12 @@ static void ieee80211_hw_roc_done(struct work_struct *work)
                return;
        }
 
-       cfg80211_remain_on_channel_expired(local->hw_roc_dev,
-                                          local->hw_roc_cookie,
-                                          local->hw_roc_channel,
-                                          local->hw_roc_channel_type,
-                                          GFP_KERNEL);
+       if (!local->hw_roc_for_tx)
+               cfg80211_remain_on_channel_expired(local->hw_roc_dev,
+                                                  local->hw_roc_cookie,
+                                                  local->hw_roc_channel,
+                                                  local->hw_roc_channel_type,
+                                                  GFP_KERNEL);
 
        local->hw_roc_channel = NULL;
        local->hw_roc_cookie = 0;