/*
 * test if there is an entry in any TX queue for which DMA is done
 * but the TX status has not been returned yet
 */
static bool rt2800usb_txstatus_pending(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;

	tx_queue_for_each(rt2x00dev, queue) {
		if (rt2x00queue_get_entry(queue, Q_INDEX_DMA_DONE) !=
		    rt2x00queue_get_entry(queue, Q_INDEX_DONE))
			return true;
	}
	return false;
}

static int rt2x00usb_dma_timeout(struct data_queue *queue)
{
    struct queue_entry *entry;

    entry = rt2x00queue_get_entry(queue, Q_INDEX_DMA_DONE);
    return rt2x00queue_dma_timeout(entry);
}

static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
			     const enum data_queue_qid queue_idx)
{
	struct data_queue *queue = rt2x00queue_get_tx_queue(rt2x00dev, queue_idx);
	struct queue_entry_priv_pci *entry_priv;
	struct queue_entry *entry;
	struct txdone_entry_desc txdesc;
	u32 word;

	while (!rt2x00queue_empty(queue)) {
		entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		entry_priv = entry->priv_data;
		rt2x00_desc_read(entry_priv->desc, 0, &word);

		if (rt2x00_get_field32(word, TXD_W0_OWNER_NIC) ||
		    !rt2x00_get_field32(word, TXD_W0_VALID))
			break;

		txdesc.flags = 0;
		switch (rt2x00_get_field32(word, TXD_W0_RESULT)) {
		case 0: 
		case 1: 
			__set_bit(TXDONE_SUCCESS, &txdesc.flags);
			break;
		case 2: 
			__set_bit(TXDONE_EXCESSIVE_RETRY, &txdesc.flags);
			
		default: 
			__set_bit(TXDONE_FAILURE, &txdesc.flags);
		}
		txdesc.retry = rt2x00_get_field32(word, TXD_W0_RETRY_COUNT);

		rt2x00lib_txdone(entry, &txdesc);
	}
}

/*
 * TX control handlers
 */
static void rt2800usb_work_txdone(struct work_struct *work)
{
	struct rt2x00_dev *rt2x00dev =
	    container_of(work, struct rt2x00_dev, txdone_work);
	struct data_queue *queue;
	struct queue_entry *entry;

	rt2800_txdone(rt2x00dev);

	/*
	 * Process any trailing TX status reports for IO failures,
	 * we loop until we find the first non-IO error entry. This
	 * can either be a frame which is free, is being uploaded,
	 * or has completed the upload but didn't have an entry
	 * in the TX_STAT_FIFO register yet.
	 */
	tx_queue_for_each(rt2x00dev, queue) {
		while (!rt2x00queue_empty(queue)) {
			entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);

			if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) ||
			    !test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
				break;

			rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE);
		}
	}
}

/*
 * Interrupt functions.
 */
static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
			     const enum ieee80211_tx_queue queue_idx)
{
	struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, queue_idx);
	struct queue_entry_priv_pci_tx *priv_tx;
	struct queue_entry *entry;
	struct txdone_entry_desc txdesc;
	u32 word;

	while (!rt2x00queue_empty(queue)) {
		entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		priv_tx = entry->priv_data;
		rt2x00_desc_read(priv_tx->desc, 0, &word);

		if (rt2x00_get_field32(word, TXD_W0_OWNER_NIC) ||
		    !rt2x00_get_field32(word, TXD_W0_VALID))
			break;

		/*
		 * Obtain the status about this packet.
		 */
		txdesc.status = rt2x00_get_field32(word, TXD_W0_RESULT);
		txdesc.retry = rt2x00_get_field32(word, TXD_W0_RETRY_COUNT);

		rt2x00pci_txdone(rt2x00dev, entry, &txdesc);
	}
}

/*
 * RX data handlers.
 */
static void rt2x00usb_work_rxdone(struct work_struct *work)
{
    struct rt2x00_dev *rt2x00dev =
        container_of(work, struct rt2x00_dev, rxdone_work);
    struct queue_entry *entry;
    struct skb_frame_desc *skbdesc;
    u8 rxd[32];

    while (!rt2x00queue_empty(rt2x00dev->rx)) {
        entry = rt2x00queue_get_entry(rt2x00dev->rx, Q_INDEX_DONE);

        if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) ||
                !test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
            break;

        /*
         * Fill in desc fields of the skb descriptor
         */
        skbdesc = get_skb_frame_desc(entry->skb);
        skbdesc->desc = rxd;
        skbdesc->desc_len = entry->queue->desc_size;

        /*
         * Send the frame to rt2x00lib for further processing.
         */
        rt2x00lib_rxdone(entry, GFP_KERNEL);
    }
}

int rt2x00usb_write_tx_data(struct rt2x00_dev *rt2x00dev,
			    struct data_queue *queue, struct sk_buff *skb,
			    struct ieee80211_tx_control *control)
{
	struct usb_device *usb_dev = rt2x00dev_usb_dev(rt2x00dev);
	struct queue_entry *entry = rt2x00queue_get_entry(queue, Q_INDEX);
	struct queue_entry_priv_usb_tx *priv_tx = entry->priv_data;
	struct skb_frame_desc *skbdesc;
	u32 length;

	if (rt2x00queue_full(queue))
		return -EINVAL;

	if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) {
		ERROR(rt2x00dev,
		      "Arrived at non-free entry in the non-full queue %d.\n"
		      "Please file bug report to %s.\n",
		      control->queue, DRV_PROJECT);
		return -EINVAL;
	}

	/*
	 * Add the descriptor in front of the skb.
	 */
	skb_push(skb, queue->desc_size);
	memset(skb->data, 0, queue->desc_size);

	/*
	 * Fill in skb descriptor
	 */
	skbdesc = get_skb_frame_desc(skb);
	skbdesc->data = skb->data + queue->desc_size;
	skbdesc->data_len = skb->len - queue->desc_size;
	skbdesc->desc = skb->data;
	skbdesc->desc_len = queue->desc_size;
	skbdesc->entry = entry;

	memcpy(&priv_tx->control, control, sizeof(priv_tx->control));
	rt2x00lib_write_tx_desc(rt2x00dev, skb, control);

	/*
	 * USB devices cannot blindly pass the skb->len as the
	 * length of the data to usb_fill_bulk_urb. Pass the skb
	 * to the driver to determine what the length should be.
	 */
	length = rt2x00dev->ops->lib->get_tx_data_len(rt2x00dev, skb);

	/*
	 * Initialize URB and send the frame to the device.
	 */
	__set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
	usb_fill_bulk_urb(priv_tx->urb, usb_dev, usb_sndbulkpipe(usb_dev, 1),
			  skb->data, length, rt2x00usb_interrupt_txdone, entry);
	usb_submit_urb(priv_tx->urb, GFP_ATOMIC);

	rt2x00queue_index_inc(queue, Q_INDEX);

	return 0;
}

/*
 * Interrupt functions.
 */
static void rt2800pci_wakeup(struct rt2x00_dev *rt2x00dev)
{
	struct ieee80211_conf conf = { .flags = 0 };
	struct rt2x00lib_conf libconf = { .conf = &conf };

	rt2800_config(rt2x00dev, &libconf, IEEE80211_CONF_CHANGE_PS);
}

static void rt2800pci_txdone(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	struct queue_entry *entry;
	u32 status;
	u8 qid;

	while (kfifo_get(&rt2x00dev->txstatus_fifo, &status)) {
		qid = rt2x00_get_field32(status, TX_STA_FIFO_PID_QUEUE);
		if (qid >= QID_RX) {
			/*
			 * Unknown queue, this shouldn't happen. Just drop
			 * this tx status.
			 */
			WARNING(rt2x00dev, "Got TX status report with "
					   "unexpected pid %u, dropping\n", qid);
			break;
		}

		queue = rt2x00queue_get_queue(rt2x00dev, qid);
		if (unlikely(queue == NULL)) {
			/*
			 * The queue is NULL, this shouldn't happen. Stop
			 * processing here and drop the tx status
			 */
			WARNING(rt2x00dev, "Got TX status for an unavailable "
					   "queue %u, dropping\n", qid);
			break;
		}

		if (rt2x00queue_empty(queue)) {
			/*
			 * The queue is empty. Stop processing here
			 * and drop the tx status.
			 */
			WARNING(rt2x00dev, "Got TX status for an empty "
					   "queue %u, dropping\n", qid);
			break;
		}

		entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		rt2800_txdone_entry(entry, status);
	}
}

static void rt2800pci_txstatus_tasklet(unsigned long data)
{
	rt2800pci_txdone((struct rt2x00_dev *)data);
}

static bool rt2800usb_txstatus_timeout(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	struct queue_entry *entry;

	tx_queue_for_each(rt2x00dev, queue) {
		entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		if (rt2800usb_entry_txstatus_timeout(entry))
			return true;
	}

static void rt2800pci_kick_queue(struct data_queue *queue)
{
	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
	struct queue_entry *entry;

	switch (queue->qid) {
	case QID_AC_VO:
	case QID_AC_VI:
	case QID_AC_BE:
	case QID_AC_BK:
		entry = rt2x00queue_get_entry(queue, Q_INDEX);
		rt2800_register_write(rt2x00dev, TX_CTX_IDX(queue->qid), entry->entry_idx);
		break;
	case QID_MGMT:
		entry = rt2x00queue_get_entry(queue, Q_INDEX);
		rt2800_register_write(rt2x00dev, TX_CTX_IDX(5), entry->entry_idx);
		break;
	default:
		break;
	}
}

/*
 * TX control handlers
 */
static void rt2800usb_work_txdone(struct work_struct *work)
{
	struct rt2x00_dev *rt2x00dev =
	    container_of(work, struct rt2x00_dev, txdone_work);
	struct data_queue *queue;
	struct queue_entry *entry;

	rt2800_txdone(rt2x00dev);

	/*
	 * Process any trailing TX status reports for IO failures,
	 * we loop until we find the first non-IO error entry. This
	 * can either be a frame which is free, is being uploaded,
	 * or has completed the upload but didn't have an entry
	 * in the TX_STAT_FIFO register yet.
	 */
	tx_queue_for_each(rt2x00dev, queue) {
		while (!rt2x00queue_empty(queue)) {
			entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);

			if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) ||
			    !test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
				break;

			if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
				rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE);
			else if (rt2x00queue_status_timeout(entry))
				rt2x00lib_txdone_noinfo(entry, TXDONE_UNKNOWN);
			else
				break;
		}
	}

	/*
	 * The hw may delay sending the packet after DMA complete
	 * if the medium is busy, thus the TX_STA_FIFO entry is
	 * also delayed -> use a timer to retrieve it.
	 */
	if (rt2800usb_txstatus_pending(rt2x00dev))
		mod_timer(&rt2x00dev->txstatus_timer, jiffies + msecs_to_jiffies(2));
}

/*
 * Interrupt functions.
 */
static void rt2400pci_txdone(struct rt2x00_dev *rt2x00dev,
			     const enum data_queue_qid queue_idx)
{
	struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, queue_idx);
	struct queue_entry_priv_pci *entry_priv;
	struct queue_entry *entry;
	struct txdone_entry_desc txdesc;
	u32 word;

	while (!rt2x00queue_empty(queue)) {
		entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		entry_priv = entry->priv_data;
		rt2x00_desc_read(entry_priv->desc, 0, &word);

		if (rt2x00_get_field32(word, TXD_W0_OWNER_NIC) ||
		    !rt2x00_get_field32(word, TXD_W0_VALID))
			break;

		/*
		 * Obtain the status about this packet.
		 */
		txdesc.flags = 0;
		switch (rt2x00_get_field32(word, TXD_W0_RESULT)) {
		case 0: /* Success */
		case 1: /* Success with retry */
			__set_bit(TXDONE_SUCCESS, &txdesc.flags);
			break;
		case 2: /* Failure, excessive retries */
			__set_bit(TXDONE_EXCESSIVE_RETRY, &txdesc.flags);
			/* Don't break, this is a failed frame! */
		default: /* Failure */
			__set_bit(TXDONE_FAILURE, &txdesc.flags);
		}
		txdesc.retry = rt2x00_get_field32(word, TXD_W0_RETRY_COUNT);

		rt2x00lib_txdone(entry, &txdesc);
	}
}

static void rt2x00usb_watchdog_reset_tx(struct data_queue *queue)
{
	struct queue_entry_priv_usb *entry_priv;
	unsigned short threshold = queue->threshold;

	WARNING(queue->rt2x00dev, "TX queue %d timed out, invoke reset", queue->qid);

	/*
	 * Temporarily disable the TX queue, this will force mac80211
	 * to use the other queues until this queue has been restored.
	 *
	 * Set the queue threshold to the queue limit. This prevents the
	 * queue from being enabled during the txdone handler.
	 */
	queue->threshold = queue->limit;
	ieee80211_stop_queue(queue->rt2x00dev->hw, queue->qid);

	/*
	 * Reset all currently uploaded TX frames.
	 */
	while (!rt2x00queue_empty(queue)) {
		entry_priv = rt2x00queue_get_entry(queue, Q_INDEX_DONE)->priv_data;
		usb_kill_urb(entry_priv->urb);

		/*
		 * We need a short delay here to wait for
		 * the URB to be canceled and invoked the tx_done handler.
		 */
		udelay(200);
	}

	/*
	 * The queue has been reset, and mac80211 is allowed to use the
	 * queue again.
	 */
	queue->threshold = threshold;
	ieee80211_wake_queue(queue->rt2x00dev->hw, queue->qid);
}

bool rt2x00pci_rxdone(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue = rt2x00dev->rx;
	struct queue_entry *entry;
	struct queue_entry_priv_pci *entry_priv;
	struct skb_frame_desc *skbdesc;
	int max_rx = 16;

	while (--max_rx) {
		entry = rt2x00queue_get_entry(queue, Q_INDEX);
		entry_priv = entry->priv_data;

		if (rt2x00dev->ops->lib->get_entry_state(entry))
			break;

		/*
		 * Fill in desc fields of the skb descriptor
		 */
		skbdesc = get_skb_frame_desc(entry->skb);
		skbdesc->desc = entry_priv->desc;
		skbdesc->desc_len = entry->queue->desc_size;

		/*
		 * DMA is already done, notify rt2x00lib that
		 * it finished successfully.
		 */
		rt2x00lib_dmastart(entry);
		rt2x00lib_dmadone(entry);

		/*
		 * Send the frame to rt2x00lib for further processing.
		 */
		rt2x00lib_rxdone(entry);
	}

	return !max_rx;
}

/*
 * Interrupt functions.
 */
static void rt2800pci_txdone(struct rt2x00_dev *rt2x00dev)
{
	struct data_queue *queue;
	struct queue_entry *entry;
	struct queue_entry *entry_done;
	struct queue_entry_priv_pci *entry_priv;
	struct txdone_entry_desc txdesc;
	u32 word;
	u32 reg;
	u32 old_reg;
	unsigned int type;
	unsigned int index;
	u16 mcs, real_mcs;

	/*
	 * During each loop we will compare the freshly read
	 * TX_STA_FIFO register value with the value read from
	 * the previous loop. If the 2 values are equal then
	 * we should stop processing because the chance it
	 * quite big that the device has been unplugged and
	 * we risk going into an endless loop.
	 */
	old_reg = 0;

	while (1) {
		rt2800_register_read(rt2x00dev, TX_STA_FIFO, &reg);
		if (!rt2x00_get_field32(reg, TX_STA_FIFO_VALID))
			break;

		if (old_reg == reg)
			break;
		old_reg = reg;

		/*
		 * Skip this entry when it contains an invalid
		 * queue identication number.
		 */
		type = rt2x00_get_field32(reg, TX_STA_FIFO_PID_TYPE) - 1;
		if (type >= QID_RX)
			continue;

		queue = rt2x00queue_get_queue(rt2x00dev, type);
		if (unlikely(!queue))
			continue;

		/*
		 * Skip this entry when it contains an invalid
		 * index number.
		 */
		index = rt2x00_get_field32(reg, TX_STA_FIFO_WCID) - 1;
		if (unlikely(index >= queue->limit))
			continue;

		entry = &queue->entries[index];
		entry_priv = entry->priv_data;
		rt2x00_desc_read((__le32 *)entry->skb->data, 0, &word);

		entry_done = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		while (entry != entry_done) {
			/*
			 * Catch up.
			 * Just report any entries we missed as failed.
			 */
			WARNING(rt2x00dev,
				"TX status report missed for entry %d\n",
				entry_done->entry_idx);

			txdesc.flags = 0;
			__set_bit(TXDONE_UNKNOWN, &txdesc.flags);
			txdesc.retry = 0;

			rt2x00lib_txdone(entry_done, &txdesc);
			entry_done = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
		}

		/*
		 * Obtain the status about this packet.
		 */
		txdesc.flags = 0;
		if (rt2x00_get_field32(reg, TX_STA_FIFO_TX_SUCCESS))
			__set_bit(TXDONE_SUCCESS, &txdesc.flags);
		else
			__set_bit(TXDONE_FAILURE, &txdesc.flags);

		/*
		 * Ralink has a retry mechanism using a global fallback
		 * table. We setup this fallback table to try immediate
		 * lower rate for all rates. In the TX_STA_FIFO,
		 * the MCS field contains the MCS used for the successfull
		 * transmission. If the first transmission succeed,
		 * we have mcs == tx_mcs. On the second transmission,
		 * we have mcs = tx_mcs - 1. So the number of
		 * retry is (tx_mcs - mcs).
		 */
		mcs = rt2x00_get_field32(word, TXWI_W0_MCS);
		real_mcs = rt2x00_get_field32(reg, TX_STA_FIFO_MCS);
		__set_bit(TXDONE_FALLBACK, &txdesc.flags);
//.........这里部分代码省略.........

/*
 * Interrupt functions.
 */
static void rt2800pci_wakeup(struct rt2x00_dev *rt2x00dev)
{
    struct ieee80211_conf conf = { .flags = 0 };
    struct rt2x00lib_conf libconf = { .conf = &conf };

    rt2800_config(rt2x00dev, &libconf, IEEE80211_CONF_CHANGE_PS);
}

static bool rt2800pci_txdone(struct rt2x00_dev *rt2x00dev)
{
    struct data_queue *queue;
    struct queue_entry *entry;
    u32 status;
    u8 qid;
    int max_tx_done = 16;

    while (kfifo_get(&rt2x00dev->txstatus_fifo, &status)) {
        qid = rt2x00_get_field32(status, TX_STA_FIFO_PID_QUEUE);
        if (unlikely(qid >= QID_RX)) {
            /*
             * Unknown queue, this shouldn't happen. Just drop
             * this tx status.
             */
            WARNING(rt2x00dev, "Got TX status report with "
                    "unexpected pid %u, dropping\n", qid);
            break;
        }

        queue = rt2x00queue_get_tx_queue(rt2x00dev, qid);
        if (unlikely(queue == NULL)) {
            /*
             * The queue is NULL, this shouldn't happen. Stop
             * processing here and drop the tx status
             */
            WARNING(rt2x00dev, "Got TX status for an unavailable "
                    "queue %u, dropping\n", qid);
            break;
        }

        if (unlikely(rt2x00queue_empty(queue))) {
            /*
             * The queue is empty. Stop processing here
             * and drop the tx status.
             */
            WARNING(rt2x00dev, "Got TX status for an empty "
                    "queue %u, dropping\n", qid);
            break;
        }

        entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
        rt2800_txdone_entry(entry, status, rt2800pci_get_txwi(entry));

        if (--max_tx_done == 0)
            break;
    }

    return !max_tx_done;
}

static inline void rt2800pci_enable_interrupt(struct rt2x00_dev *rt2x00dev,
        struct rt2x00_field32 irq_field)
{
    u32 reg;

    /*
     * Enable a single interrupt. The interrupt mask register
     * access needs locking.
     */
    spin_lock_irq(&rt2x00dev->irqmask_lock);
    rt2x00pci_register_read(rt2x00dev, INT_MASK_CSR, &reg);
    rt2x00_set_field32(&reg, irq_field, 1);
    rt2x00pci_register_write(rt2x00dev, INT_MASK_CSR, reg);
    spin_unlock_irq(&rt2x00dev->irqmask_lock);
}