[PATCH v3 23/41] net: mac802154: Follow the count of ongoing transmissions

[Miquel Raynal <miquel.raynal@bootlin.com>]

In order to create a synchronous API for MLME command purposes, we need
to be able to track the end of the ongoing transmissions. Let's
introduce an atomic variable which is incremented and decremented when
relevant and now at any moment if a there is an ongoing transmission.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
---
 include/net/cfg802154.h | 3 +++
 net/mac802154/tx.c      | 3 +++
 net/mac802154/util.c    | 1 +
 3 files changed, 7 insertions(+)

diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
index 0b8b1812cea1..969cae56b000 100644
--- a/include/net/cfg802154.h
+++ b/include/net/cfg802154.h
@@ -283,6 +283,9 @@ struct wpan_phy {
 	/* the network namespace this phy lives in currently */
 	possible_net_t _net;
 
+	/* Transmission monitoring */
+	atomic_t ongoing_txs;
+
 	char priv[] __aligned(NETDEV_ALIGN);
 };
 
diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
index a01689ddd547..731e86bfe73f 100644
--- a/net/mac802154/tx.c
+++ b/net/mac802154/tx.c
@@ -45,6 +45,7 @@ void ieee802154_xmit_sync_worker(struct work_struct *work)
 	/* Restart the netif queue on each sub_if_data object. */
 	ieee802154_wake_queue(&local->hw);
 	kfree_skb(skb);
+	atomic_dec(&local->phy->ongoing_txs);
 	netdev_dbg(dev, "transmission failed\n");
 }
 
@@ -80,6 +81,7 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
 	 * cases they only provide a sync callback which we will use as a
 	 * fallback.
 	 */
+	atomic_inc(&local->phy->ongoing_txs);
 	if (local->ops->xmit_async) {
 		unsigned int len = skb->len;
 
@@ -99,6 +101,7 @@ ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
 	return NETDEV_TX_OK;
 
 err_tx:
+	atomic_dec(&local->phy->ongoing_txs);
 	kfree_skb(skb);
 	return NETDEV_TX_OK;
 }
diff --git a/net/mac802154/util.c b/net/mac802154/util.c
index e093ccaebd76..0fa538b0debc 100644
--- a/net/mac802154/util.c
+++ b/net/mac802154/util.c
@@ -83,6 +83,7 @@ void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb,
 	}
 
 	dev_consume_skb_any(skb);
+	atomic_dec(&hw->phy->ongoing_txs);
 }
 EXPORT_SYMBOL(ieee802154_xmit_complete);
 
-- 
2.27.0