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Commit 3517afde authored by Herton Ronaldo Krzesinski's avatar Herton Ronaldo Krzesinski Committed by John W. Linville
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rtl8187: feedback transmitted packets using tx close descriptor for 8187B 



Realtek 8187B has a receive command queue to feedback beacon interrupt
and transmitted packet status. Use it to feedback mac80211 about status
of transmitted packets. Unfortunately in the course of testing I found
that the sequence number reported by hardware includes entire sequence
control in a 12 bit only field, so a workaround is done to check only
lowest bits.

Tested-by: default avatarLarry Finger <Larry.Finger@lwfinger.net>
Tested-by: default avatarHin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: default avatarHerton Ronaldo Krzesinski <herton@mandriva.com.br>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent b4572a92

drivers/net/wireless/rtl818x/rtl8187.h

+5 −0
Original line number Diff line number Diff line
@@ -113,6 +113,11 @@ struct rtl8187_priv { 
	u8 noise;

	u8 slot_time;

	u8 aifsn[4];

	struct {

		__le64 buf;

		struct urb *urb;

		struct sk_buff_head queue;

	} b_tx_status;

};



void rtl8187_write_phy(struct ieee80211_hw *dev, u8 addr, u32 data);

drivers/net/wireless/rtl818x/rtl8187_dev.c

+131 −4
Original line number Diff line number Diff line
@@ -176,9 +176,28 @@ static void rtl8187_tx_cb(struct urb *urb) 
	skb_pull(skb, priv->is_rtl8187b ? sizeof(struct rtl8187b_tx_hdr) :

					  sizeof(struct rtl8187_tx_hdr));

	ieee80211_tx_info_clear_status(info);



	if (!urb->status &&

	    !(info->flags & IEEE80211_TX_CTL_NO_ACK) &&

	    priv->is_rtl8187b) {

		skb_queue_tail(&priv->b_tx_status.queue, skb);



		/* queue is "full", discard last items */

		while (skb_queue_len(&priv->b_tx_status.queue) > 5) {

			struct sk_buff *old_skb;



			dev_dbg(&priv->udev->dev,

				"transmit status queue full\n");



			old_skb = skb_dequeue(&priv->b_tx_status.queue);

			ieee80211_tx_status_irqsafe(hw, old_skb);

		}

	} else {

		if (!(info->flags & IEEE80211_TX_CTL_NO_ACK) && !urb->status)

			info->flags |= IEEE80211_TX_STAT_ACK;

		ieee80211_tx_status_irqsafe(hw, skb);

	}

}



static int rtl8187_tx(struct ieee80211_hw *dev, struct sk_buff *skb)

{
@@ -219,7 +238,7 @@ static int rtl8187_tx(struct ieee80211_hw *dev, struct sk_buff *skb) 
		hdr->flags = cpu_to_le32(flags);

		hdr->len = 0;

		hdr->rts_duration = rts_dur;

		hdr->retry = cpu_to_le32((info->control.rates[0].count - 1) << 8);

		hdr->retry = cpu_to_le32(info->control.rates[0].count << 8);

		buf = hdr;



		ep = 2;
@@ -237,7 +256,7 @@ static int rtl8187_tx(struct ieee80211_hw *dev, struct sk_buff *skb) 
		memset(hdr, 0, sizeof(*hdr));

		hdr->flags = cpu_to_le32(flags);

		hdr->rts_duration = rts_dur;

		hdr->retry = cpu_to_le32((info->control.rates[0].count - 1) << 8);

		hdr->retry = cpu_to_le32(info->control.rates[0].count << 8);

		hdr->tx_duration =

			ieee80211_generic_frame_duration(dev, priv->vif,

							 skb->len, txrate);
@@ -403,6 +422,109 @@ static int rtl8187_init_urbs(struct ieee80211_hw *dev) 
	return 0;

}



static void rtl8187b_status_cb(struct urb *urb)

{

	struct ieee80211_hw *hw = (struct ieee80211_hw *)urb->context;

	struct rtl8187_priv *priv = hw->priv;

	u64 val;

	unsigned int cmd_type;



	if (unlikely(urb->status)) {

		usb_free_urb(urb);

		return;

	}



	/*

	 * Read from status buffer:

	 *

	 * bits [30:31] = cmd type:

	 * - 0 indicates tx beacon interrupt

	 * - 1 indicates tx close descriptor

	 *

	 * In the case of tx beacon interrupt:

	 * [0:9] = Last Beacon CW

	 * [10:29] = reserved

	 * [30:31] = 00b

	 * [32:63] = Last Beacon TSF

	 *

	 * If it's tx close descriptor:

	 * [0:7] = Packet Retry Count

	 * [8:14] = RTS Retry Count

	 * [15] = TOK

	 * [16:27] = Sequence No

	 * [28] = LS

	 * [29] = FS

	 * [30:31] = 01b

	 * [32:47] = unused (reserved?)

	 * [48:63] = MAC Used Time

	 */

	val = le64_to_cpu(priv->b_tx_status.buf);



	cmd_type = (val >> 30) & 0x3;

	if (cmd_type == 1) {

		unsigned int pkt_rc, seq_no;

		bool tok;

		struct sk_buff *skb;

		struct ieee80211_hdr *ieee80211hdr;

		unsigned long flags;



		pkt_rc = val & 0xFF;

		tok = val & (1 << 15);

		seq_no = (val >> 16) & 0xFFF;



		spin_lock_irqsave(&priv->b_tx_status.queue.lock, flags);

		skb_queue_reverse_walk(&priv->b_tx_status.queue, skb) {

			ieee80211hdr = (struct ieee80211_hdr *)skb->data;



			/*

			 * While testing, it was discovered that the seq_no

			 * doesn't actually contains the sequence number.

			 * Instead of returning just the 12 bits of sequence

			 * number, hardware is returning entire sequence control

			 * (fragment number plus sequence number) in a 12 bit

			 * only field overflowing after some time. As a

			 * workaround, just consider the lower bits, and expect

			 * it's unlikely we wrongly ack some sent data

			 */

			if ((le16_to_cpu(ieee80211hdr->seq_ctrl)

			    & 0xFFF) == seq_no)

				break;

		}

		if (skb != (struct sk_buff *) &priv->b_tx_status.queue) {

			struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);



			__skb_unlink(skb, &priv->b_tx_status.queue);

			if (tok)

				info->flags |= IEEE80211_TX_STAT_ACK;

			info->status.rates[0].count = pkt_rc;



			ieee80211_tx_status_irqsafe(hw, skb);

		}

		spin_unlock_irqrestore(&priv->b_tx_status.queue.lock, flags);

	}



	usb_submit_urb(urb, GFP_ATOMIC);

}



static int rtl8187b_init_status_urb(struct ieee80211_hw *dev)

{

	struct rtl8187_priv *priv = dev->priv;

	struct urb *entry;



	entry = usb_alloc_urb(0, GFP_KERNEL);

	if (!entry)

		return -ENOMEM;

	priv->b_tx_status.urb = entry;



	usb_fill_bulk_urb(entry, priv->udev, usb_rcvbulkpipe(priv->udev, 9),

			  &priv->b_tx_status.buf, sizeof(priv->b_tx_status.buf),

			  rtl8187b_status_cb, dev);



	usb_submit_urb(entry, GFP_KERNEL);



	return 0;

}



static int rtl8187_cmd_reset(struct ieee80211_hw *dev)

{

	struct rtl8187_priv *priv = dev->priv;
@@ -755,6 +877,7 @@ static int rtl8187_start(struct ieee80211_hw *dev) 
				  (7 << 0  /* long retry limit */) |

				  (7 << 21 /* MAX TX DMA */));

		rtl8187_init_urbs(dev);

		rtl8187b_init_status_urb(dev);

		mutex_unlock(&priv->conf_mutex);

		return 0;

	}
@@ -831,6 +954,9 @@ static void rtl8187_stop(struct ieee80211_hw *dev) 
		usb_kill_urb(info->urb);

		kfree_skb(skb);

	}

	while ((skb = skb_dequeue(&priv->b_tx_status.queue)))

		dev_kfree_skb_any(skb);

	usb_kill_urb(priv->b_tx_status.urb);

	mutex_unlock(&priv->conf_mutex);

}
@@ -1317,6 +1443,7 @@ static int __devinit rtl8187_probe(struct usb_interface *intf, 
		goto err_free_dev;

	}

	mutex_init(&priv->conf_mutex);

	skb_queue_head_init(&priv->b_tx_status.queue);



	printk(KERN_INFO "%s: hwaddr %pM, %s V%d + %s\n",

	       wiphy_name(dev->wiphy), dev->wiphy->perm_addr,