linux/net/mac802154/tx.c
Alexander Aring 61f2dcba9a 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>
2014-11-13 04:51:58 +01:00

149 lines
3.5 KiB
C

/*
* Copyright 2007-2012 Siemens AG
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Written by:
* Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
* Sergey Lapin <slapin@ossfans.org>
* Maxim Gorbachyov <maxim.gorbachev@siemens.com>
* Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
*/
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/crc-ccitt.h>
#include <asm/unaligned.h>
#include <net/rtnetlink.h>
#include <net/ieee802154_netdev.h>
#include <net/mac802154.h>
#include <net/cfg802154.h>
#include "ieee802154_i.h"
#include "driver-ops.h"
/* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
* packets through the workqueue.
*/
struct ieee802154_xmit_cb {
struct sk_buff *skb;
struct work_struct work;
struct ieee802154_local *local;
};
static struct ieee802154_xmit_cb ieee802154_xmit_cb;
static void ieee802154_xmit_worker(struct work_struct *work)
{
struct ieee802154_xmit_cb *cb =
container_of(work, struct ieee802154_xmit_cb, work);
struct ieee802154_local *local = cb->local;
struct sk_buff *skb = cb->skb;
struct net_device *dev = skb->dev;
int res;
rtnl_lock();
/* check if ifdown occurred while schedule */
if (!netif_running(dev))
goto err_tx;
res = drv_xmit_sync(local, skb);
if (res)
goto err_tx;
ieee802154_xmit_complete(&local->hw, skb, false);
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
rtnl_unlock();
return;
err_tx:
/* Restart the netif queue on each sub_if_data object. */
ieee802154_wake_queue(&local->hw);
rtnl_unlock();
kfree_skb(skb);
netdev_dbg(dev, "transmission failed\n");
}
static netdev_tx_t
ieee802154_tx(struct ieee802154_local *local, struct sk_buff *skb)
{
struct net_device *dev = skb->dev;
int ret;
if (!(local->hw.flags & IEEE802154_HW_TX_OMIT_CKSUM)) {
u16 crc = crc_ccitt(0, skb->data, skb->len);
put_unaligned_le16(crc, skb_put(skb, 2));
}
if (skb_cow_head(skb, local->hw.extra_tx_headroom))
goto err_tx;
/* Stop the netif queue on each sub_if_data object. */
ieee802154_stop_queue(&local->hw);
/* async is priority, otherwise sync is fallback */
if (local->ops->xmit_async) {
ret = drv_xmit_async(local, skb);
if (ret) {
ieee802154_wake_queue(&local->hw);
goto err_tx;
}
dev->stats.tx_packets++;
dev->stats.tx_bytes += skb->len;
} else {
INIT_WORK(&ieee802154_xmit_cb.work, ieee802154_xmit_worker);
ieee802154_xmit_cb.skb = skb;
ieee802154_xmit_cb.local = local;
queue_work(local->workqueue, &ieee802154_xmit_cb.work);
}
return NETDEV_TX_OK;
err_tx:
kfree_skb(skb);
return NETDEV_TX_OK;
}
netdev_tx_t
ieee802154_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
skb->skb_iif = dev->ifindex;
return ieee802154_tx(sdata->local, skb);
}
netdev_tx_t
ieee802154_subif_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct ieee802154_sub_if_data *sdata = IEEE802154_DEV_TO_SUB_IF(dev);
int rc;
rc = mac802154_llsec_encrypt(&sdata->sec, skb);
if (rc) {
netdev_warn(dev, "encryption failed: %i\n", rc);
kfree_skb(skb);
return NETDEV_TX_OK;
}
skb->skb_iif = dev->ifindex;
return ieee802154_tx(sdata->local, skb);
}