[PATCH v2 1/2] wifi: mac80211: export ieee80211_purge_tx_queue() for drivers

[Ping-Ke Shih <pkshih@realtek.com>]

Drivers need to purge TX SKB when stopping. Using skb_queue_purge() can't
report TX status to mac80211, causing ieee80211_free_ack_frame() warns
"Have pending ack frames!". Export ieee80211_purge_tx_queue() for drivers
to not have to reimplement it.

Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
v2:
  - correct wording in commit message, and mention reason why we export
    the symbol
  - add comment to note ieee80211_purge_tx_queue() doesn't take locks
  - remove prototype from net/mac80211/ieee80211_i.h 
---
 include/net/mac80211.h     | 13 +++++++++++++
 net/mac80211/ieee80211_i.h |  2 --
 net/mac80211/status.c      |  1 +
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0a04eaf5343c..651fa926c94a 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -3180,6 +3180,19 @@ ieee80211_get_alt_retry_rate(const struct ieee80211_hw *hw,
  */
 void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
 
+/**
+ * ieee80211_purge_tx_queue - purge TX skb queue
+ * @hw: the hardware
+ * @skbs: the skbs
+ *
+ * Free a set of transmit skbs. Use this function when device is going to stop
+ * but some transmit skbs without TX status are still queued.
+ * This function does not take the list lock and the caller must hold the
+ * relevant locks to use it.
+ */
+void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
+			      struct sk_buff_head *skbs);
+
 /**
  * DOC: Hardware crypto acceleration
  *
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index a3485e4c6132..da705bf50d93 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -2072,8 +2072,6 @@ void __ieee80211_subif_start_xmit(struct sk_buff *skb,
 				  u32 info_flags,
 				  u32 ctrl_flags,
 				  u64 *cookie);
-void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
-			      struct sk_buff_head *skbs);
 struct sk_buff *
 ieee80211_build_data_template(struct ieee80211_sub_if_data *sdata,
 			      struct sk_buff *skb, u32 info_flags);
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index dd8f857a1fbc..d1cf987de13b 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -1301,3 +1301,4 @@ void ieee80211_purge_tx_queue(struct ieee80211_hw *hw,
 	while ((skb = __skb_dequeue(skbs)))
 		ieee80211_free_txskb(hw, skb);
 }
+EXPORT_SYMBOL(ieee80211_purge_tx_queue);
-- 
2.25.1