传输途径 ath9k层到硬件层

这里只写了ath9k层到虚拟硬件层的一些东西，mac层的没有整理。

传输途径主要从ath9k_tx() --->ath_tx_start() --->ath_tx_send_normal() --->ath_tx_txqaddbuf()---->ath9k_hw_txstart()

ath9k_tx（）（main.c）：

static void ath9k_tx(struct ieee80211_hw *hw,

struct ieee80211_tx_control *control,

struct sk_buff *skb)

{

struct ath_softc *sc = hw->priv;

struct ath_common *common = ath9k_hw_common(sc->sc_ah);

struct ath_tx_control txctl;

struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;

unsigned long flags;

if (sc->ps_enabled) {

/*

* mac80211 does not set PM field for normal data frames, so we

* need to update that based on the current PS mode.

*/

//加载结构ath_sofc中硬件的详细信息和更新PM位

if (ieee80211_is_data(hdr->frame_control) &&

!ieee80211_is_nullfunc(hdr->frame_control) &&

!ieee80211_has_pm(hdr->frame_control)) {

ath_dbg(common, PS,

"Add PM=1 for a TX frame while in PS mode\n");

hdr->frame_control |= cpu_to_le16(IEEE80211_FCTL_PM);

}

}

if (unlikely(sc->sc_ah->power_mode == ATH9K_PM_NETWORK_SLEEP)) {

/*

* We are using PS-Poll and mac80211 can request TX while in

* power save mode. Need to wake up hardware for the TX to be

* completed and if needed, also for RX of buffered frames.

*/

ath9k_ps_wakeup(sc); //唤醒正在休眠的硬件

spin_lock_irqsave(&sc->sc_pm_lock, flags);

if (!(sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP))

ath9k_hw_setrxabort(sc->sc_ah, 0);

if (ieee80211_is_pspoll(hdr->frame_control)) {

ath_dbg(common, PS,

"Sending PS-Poll to pick a buffered frame\n");

sc->ps_flags |= PS_WAIT_FOR_PSPOLL_DATA;

} else {

ath_dbg(common, PS, "Wake up to complete TX\n");

sc->ps_flags |= PS_WAIT_FOR_TX_ACK;

}

/*

* The actual restore operation will happen only after

* the ps_flags bit is cleared. We are just dropping

* the ps_usecount here.

*/

spin_unlock_irqrestore(&sc->sc_pm_lock, flags);

ath9k_ps_restore(sc);

}

/*

* Cannot tx while the hardware is in full sleep, it first needs a full

* chip reset to recover from that

*/

if (unlikely(sc->sc_ah->power_mode == ATH9K_PM_FULL_SLEEP)) {

ath_err(common, "TX while HW is in FULL_SLEEP mode\n");

goto exit;

}

//用数据结构ath_tx_control跟踪传输状态

memset(&txctl, 0, sizeof(struct ath_tx_control));

txctl.txq = sc->tx.txq_map[skb_get_queue_mapping(skb)];

txctl.sta = control->sta;

ath_dbg(common, XMIT, "transmitting packet, skb: %p\n", skb);

//这里进入下一步的传输，在ath_tx_start中启动传输

if (ath_tx_start(hw, skb, &txctl) != 0) {

ath_dbg(common, XMIT, "TX failed\n");

TX_STAT_INC(txctl.txq->axq_qnum, txfailed);

goto exit;

}

return;

exit:

ieee80211_free_txskb(hw, skb);

}