On Friday 31 October 2008 22:07:45 Hin-Tak Leung wrote:
> --- On Fri, 31/10/08, Larry Finger <Larry.Finger@xxxxxxxxxxxx> wrote:
> > With these patches installed, my RTL8187B device was stuck
> > at 1 Mbs using the
> > 'pid' algorithm. Without them, the rate rapidly
> > increases to 54 Mbs. I'm roughly
> > 2 m from my AP, and get an indicated signal of -22 dBm and
> > a link quality of
> > 98/100. My kernel is from wireless-testing
> > (v2.6.28-rc2-4159-g6c11cd2) with the
> > rtl8187 power control and timing patches submitted earlier.
> > There are no changes
> > to any of the mac80211 components.
>
> This behavior was mentioned in Herton's e-mail, and said to be likely due
> to recent rewrite of the rate-control api?
>
> I am still using the early incarnation of the rate-control patch with
> 2.6.26.7-86.fc9.x86_64 and 2.6.27.4-69.fc10.x86_64 (by rolling back
> wireless-testing to 2.6.27.x to match), and my rate does go up and down
> (between 11M to 36M just now) and generally feels more responsive.
> Apologies I haven't looked at the newly posted rate-control patch yet - is
> there any significant code difference?
Yes, cleanups, minor optimization and fixes, like freeing skbs in status queue
on interface stop, btw this was the patch for wireless-testing from some days
ago while still in 2.6.27 (different from previous version I sent privately with
printks/debug):
diff --git a/drivers/net/wireless/rtl8187.h b/drivers/net/wireless/rtl8187.h
index f09872e..c385407 100644
--- a/drivers/net/wireless/rtl8187.h
+++ b/drivers/net/wireless/rtl8187.h
@@ -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);
diff --git a/drivers/net/wireless/rtl8187_dev.c b/drivers/net/wireless/rtl8187_dev.c
index 537ad64..4d692d4 100644
--- a/drivers/net/wireless/rtl8187_dev.c
+++ b/drivers/net/wireless/rtl8187_dev.c
@@ -167,8 +167,34 @@ 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);
- info->flags |= IEEE80211_TX_STAT_ACK;
- ieee80211_tx_status_irqsafe(hw, skb);
+
+ 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;
+ struct ieee80211_tx_info *old_info;
+
+ dev_dbg(&priv->udev->dev,
+ "transmit status queue full\n");
+
+ old_skb = skb_dequeue(&priv->b_tx_status.queue);
+ old_info = IEEE80211_SKB_CB(old_skb);
+ old_info->status.excessive_retries = 1;
+ ieee80211_tx_status_irqsafe(hw, old_skb);
+ }
+ } else {
+ if (!(info->flags & IEEE80211_TX_CTL_NO_ACK)) {
+ if (!urb->status)
+ info->flags |= IEEE80211_TX_STAT_ACK;
+ else
+ info->status.excessive_retries = 1;
+ }
+ ieee80211_tx_status_irqsafe(hw, skb);
+ }
}
static int rtl8187_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
@@ -394,6 +420,107 @@ 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;
+
+ /*
+ * Instead of returning just the 12 bits of sequence
+ * number, hardware is returning entire sequence
+ * control, 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;
+ else
+ info->status.excessive_retries = 1;
+ info->status.retry_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;
@@ -746,6 +873,7 @@ 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;
}
@@ -822,6 +950,9 @@ 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);
}
@@ -1310,6 +1441,7 @@ 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 %s, %s V%d + %s\n",
wiphy_name(dev->wiphy), print_mac(mac, dev->wiphy->perm_addr),
--
1.6.0.2
>
> Hin-Tak
>
> Hin-Tak
--
[]'s
Herton
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
