2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-28 15:13:55 +08:00
linux-next/net/mac802154/tx.c
Alan Ott 9f7f78b479 mac802154: Keep track of the channel when changed
Two sections checked whether the current channel != the new channel
without ever setting the current channel variables.

1. net/mac802154/tx.c: Prevent set_channel() from getting called every
time a packet is sent.

2. net/mac802154/mib.c: Lock (pib_lock) accesses to current_channel and
current_page and make sure they are updated when the channel has been
changed.

Signed-off-by: Alan Ott <alan@signal11.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-08 12:09:18 -04:00

132 lines
3.3 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* 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 <net/ieee802154_netdev.h>
#include <net/mac802154.h>
#include <net/wpan-phy.h>
#include "mac802154.h"
/* IEEE 802.15.4 transceivers can sleep during the xmit session, so process
* packets through the workqueue.
*/
struct xmit_work {
struct sk_buff *skb;
struct work_struct work;
struct mac802154_priv *priv;
u8 chan;
u8 page;
};
static void mac802154_xmit_worker(struct work_struct *work)
{
struct xmit_work *xw = container_of(work, struct xmit_work, work);
struct mac802154_sub_if_data *sdata;
int res;
mutex_lock(&xw->priv->phy->pib_lock);
if (xw->priv->phy->current_channel != xw->chan ||
xw->priv->phy->current_page != xw->page) {
res = xw->priv->ops->set_channel(&xw->priv->hw,
xw->page,
xw->chan);
if (res) {
pr_debug("set_channel failed\n");
goto out;
}
xw->priv->phy->current_channel = xw->chan;
xw->priv->phy->current_page = xw->page;
}
res = xw->priv->ops->xmit(&xw->priv->hw, xw->skb);
if (res)
pr_debug("transmission failed\n");
out:
mutex_unlock(&xw->priv->phy->pib_lock);
/* Restart the netif queue on each sub_if_data object. */
rcu_read_lock();
list_for_each_entry_rcu(sdata, &xw->priv->slaves, list)
netif_wake_queue(sdata->dev);
rcu_read_unlock();
dev_kfree_skb(xw->skb);
kfree(xw);
}
netdev_tx_t mac802154_tx(struct mac802154_priv *priv, struct sk_buff *skb,
u8 page, u8 chan)
{
struct xmit_work *work;
struct mac802154_sub_if_data *sdata;
if (!(priv->phy->channels_supported[page] & (1 << chan))) {
WARN_ON(1);
kfree_skb(skb);
return NETDEV_TX_OK;
}
mac802154_monitors_rx(mac802154_to_priv(&priv->hw), skb);
if (!(priv->hw.flags & IEEE802154_HW_OMIT_CKSUM)) {
u16 crc = crc_ccitt(0, skb->data, skb->len);
u8 *data = skb_put(skb, 2);
data[0] = crc & 0xff;
data[1] = crc >> 8;
}
if (skb_cow_head(skb, priv->hw.extra_tx_headroom)) {
kfree_skb(skb);
return NETDEV_TX_OK;
}
work = kzalloc(sizeof(struct xmit_work), GFP_ATOMIC);
if (!work) {
kfree_skb(skb);
return NETDEV_TX_BUSY;
}
/* Stop the netif queue on each sub_if_data object. */
rcu_read_lock();
list_for_each_entry_rcu(sdata, &priv->slaves, list)
netif_stop_queue(sdata->dev);
rcu_read_unlock();
INIT_WORK(&work->work, mac802154_xmit_worker);
work->skb = skb;
work->priv = priv;
work->page = page;
work->chan = chan;
queue_work(priv->dev_workqueue, &work->work);
return NETDEV_TX_OK;
}