mac802154: tx: add support for xmit_async callback

This patch renames the existsing xmit callback to xmit_sync and
introduces an asynchronous xmit_async function. If ieee802154_ops
doesn't provide the xmit_async callback, then we have a fallback to
the xmit_sync callback.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Cc: Alan Ott <alan@signal11.us>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

7 files changed, 35 insertions, 14 deletions

diff --git a/drivers/net/ieee802154/at86rf230.c b/drivers/net/ieee802154/at86rf230.c
index b0d68d7061c1..06a3e9013d60 100644
--- a/drivers/net/ieee802154/at86rf230.c
+++ b/drivers/net/ieee802154/at86rf230.c
@@ -1237,7 +1237,7 @@ at86rf230_set_frame_retries(struct ieee802154_hw *hw, s8 retries)
 
 static struct ieee802154_ops at86rf230_ops = {
         .owner = THIS_MODULE,
-        .xmit = at86rf230_xmit,
+        .xmit_sync = at86rf230_xmit,
         .ed = at86rf230_ed,
         .set_channel = at86rf230_channel,
         .start = at86rf230_start,
diff --git a/drivers/net/ieee802154/cc2520.c b/drivers/net/ieee802154/cc2520.c
index b827e04d481b..f6f07f4eb0ec 100644
--- a/drivers/net/ieee802154/cc2520.c
+++ b/drivers/net/ieee802154/cc2520.c
@@ -635,7 +635,7 @@ static struct ieee802154_ops cc2520_ops = {
         .owner = THIS_MODULE,
         .start = cc2520_start,
         .stop = cc2520_stop,
-        .xmit = cc2520_tx,
+        .xmit_sync = cc2520_tx,
         .ed = cc2520_ed,
         .set_channel = cc2520_set_channel,
         .set_hw_addr_filt = cc2520_filter,
diff --git a/drivers/net/ieee802154/fakelb.c b/drivers/net/ieee802154/fakelb.c
index 51e3c589d2e4..db0703f0fa41 100644
--- a/drivers/net/ieee802154/fakelb.c
+++ b/drivers/net/ieee802154/fakelb.c
@@ -131,7 +131,7 @@ fakelb_hw_stop(struct ieee802154_hw *hw) {
 
 static struct ieee802154_ops fakelb_ops = {
         .owner = THIS_MODULE,
-        .xmit = fakelb_hw_xmit,
+        .xmit_sync = fakelb_hw_xmit,
         .ed = fakelb_hw_ed,
         .set_channel = fakelb_hw_channel,
         .start = fakelb_hw_start,
diff --git a/drivers/net/ieee802154/mrf24j40.c b/drivers/net/ieee802154/mrf24j40.c
index 2e267c5c44da..3d775afa217f 100644
--- a/drivers/net/ieee802154/mrf24j40.c
+++ b/drivers/net/ieee802154/mrf24j40.c
@@ -581,7 +581,7 @@ out:
 
 static struct ieee802154_ops mrf24j40_ops = {
         .owner = THIS_MODULE,
-        .xmit = mrf24j40_tx,
+        .xmit_sync = mrf24j40_tx,
         .ed = mrf24j40_ed,
         .start = mrf24j40_start,
         .stop = mrf24j40_stop,
diff --git a/include/net/mac802154.h b/include/net/mac802154.h
index 29af5c346ebf..57b120281afc 100644
--- a/include/net/mac802154.h
+++ b/include/net/mac802154.h
@@ -109,7 +109,16 @@ struct ieee802154_hw {
  * stop:  Handler that 802.15.4 module calls for device cleanup.
  *        This function is called after the last interface is removed.
  *
- * xmit:  Handler that 802.15.4 module calls for each transmitted frame.
+ * xmit_sync:
+ *        Handler that 802.15.4 module calls for each transmitted frame.
+ *        skb cntains the buffer starting from the IEEE 802.15.4 header.
+ *        The low-level driver should send the frame based on available
+ *        configuration. This is called by a workqueue and useful for
+ *        synchronous 802.15.4 drivers.
+ *        This function should return zero or negative errno.
+ *
+ * xmit_async:
+ *        Handler that 802.15.4 module calls for each transmitted frame.
  *        skb cntains the buffer starting from the IEEE 802.15.4 header.
  *        The low-level driver should send the frame based on available
  *        configuration.
@@ -160,8 +169,10 @@ struct ieee802154_ops {
         struct module   *owner;
         int             (*start)(struct ieee802154_hw *hw);
         void            (*stop)(struct ieee802154_hw *hw);
-        int             (*xmit)(struct ieee802154_hw *hw,
-                                struct sk_buff *skb);
+        int             (*xmit_sync)(struct ieee802154_hw *hw,
+                                     struct sk_buff *skb);
+        int             (*xmit_async)(struct ieee802154_hw *hw,
+                                      struct sk_buff *skb);
         int             (*ed)(struct ieee802154_hw *hw, u8 *level);
         int             (*set_channel)(struct ieee802154_hw *hw,
                                        int page,
diff --git a/net/mac802154/main.c b/net/mac802154/main.c
index 0e9a6a203f7a..3c0a824d24ac 100644
--- a/net/mac802154/main.c
+++ b/net/mac802154/main.c
@@ -229,8 +229,8 @@ ieee802154_alloc_hw(size_t priv_data_len, struct ieee802154_ops *ops)
         struct ieee802154_local *local;
         size_t priv_size;
 
-        if (!ops || !ops->xmit || !ops->ed || !ops->start ||
-            !ops->stop || !ops->set_channel) {
+        if (!ops || !(ops->xmit_async || ops->xmit_sync) || !ops->ed ||
+            !ops->start || !ops->stop || !ops->set_channel) {
                 pr_err("undefined IEEE802.15.4 device operations\n");
                 return NULL;
         }
diff --git a/net/mac802154/tx.c b/net/mac802154/tx.c
index 23139cae0764..1a4f6d91ab8c 100644
--- a/net/mac802154/tx.c
+++ b/net/mac802154/tx.c
@@ -50,7 +50,7 @@ static void mac802154_xmit_worker(struct work_struct *work)
         struct sk_buff *skb = cb->skb;
         int res;
 
-        res = local->ops->xmit(&local->hw, skb);
+        res = local->ops->xmit_sync(&local->hw, skb);
         if (res) {
                 pr_debug("transmission failed\n");
                 /* Restart the netif queue on each sub_if_data object. */
@@ -66,6 +66,7 @@ static netdev_tx_t
 mac802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
 {
         struct wpan_xmit_cb *cb = wpan_xmit_cb(skb);
+        int ret;
 
         mac802154_monitors_rx(local, skb);
 
@@ -83,11 +84,20 @@ mac802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
         /* Stop the netif queue on each sub_if_data object. */
         ieee802154_stop_queue(&local->hw);
 
-        INIT_WORK(&cb->work, mac802154_xmit_worker);
-        cb->skb = skb;
-        cb->local = local;
+        /* async is priority, otherwise sync is fallback */
+        if (local->ops->xmit_async) {
+                ret = local->ops->xmit_async(&local->hw, skb);
+                if (ret) {
+                        ieee802154_wake_queue(&local->hw);
+                        goto err_tx;
+                }
+        } else {
+                INIT_WORK(&cb->work, mac802154_xmit_worker);
+                cb->skb = skb;
+                cb->local = local;
 
-        queue_work(local->workqueue, &cb->work);
+                queue_work(local->workqueue, &cb->work);
+        }
 
         return NETDEV_TX_OK;