mac802154: add interframe spacing time handling

This patch adds a new interframe spacing time handling into mac802154
layer. Interframe spacing time is a time period between each transmit.
This patch adds a high resolution timer into mac802154 and starts on
xmit complete with corresponding interframe spacing expire time if
ifs_handling is true. We make it variable because it depends if
interframe spacing time is handled by transceiver or mac802154. At the
timer complete function we wake the netdev queue again. This avoids
new frame transmit in range of interframe spacing time.

For synced driver we add no handling of interframe spacing time. This
is currently a lack of support in all synced xmit drivers. I suppose
it's working because the latency of workqueue which is needed to call
spi_sync.

Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/mac802154/ieee802154_i.h b/net/mac802154/ieee802154_i.h
index 69cb585e162f..c5b231047b60 100644
--- a/net/mac802154/ieee802154_i.h
+++ b/net/mac802154/ieee802154_i.h
@@ -20,6 +20,7 @@
 #define __IEEE802154_I_H
 
 #include <linux/mutex.h>
+#include <linux/hrtimer.h>
 #include <net/cfg802154.h>
 #include <net/mac802154.h>
 #include <net/ieee802154_netdev.h>
@@ -51,6 +52,8 @@ struct ieee802154_local {
          */
         struct workqueue_struct *workqueue;
 
+        struct hrtimer ifs_timer;
+
         bool started;
 
         struct tasklet_struct tasklet;
@@ -127,6 +130,7 @@ ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
 void mac802154_wpan_setup(struct net_device *dev);
 netdev_tx_t
 ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
+enum hrtimer_restart ieee802154_xmit_ifs_timer(struct hrtimer *timer);
 
 /* MIB callbacks */
 void mac802154_dev_set_short_addr(struct net_device *dev, __le16 val);