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>

1 files changed, 59 insertions, 0 deletions

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 168a6ba8fc28..4bc8a9250cfd 100644
--- 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;