rtl8187: Change rate-control feedback

The driver for the RTL8187L chips returns IEEE80211_TX_STAT_ACK for all
packets, even if the maximum number of retries was exhausted. In addition
it fails to setup max_rates in the ieee80211_hw struct, This behavior
may be responsible for the problems noted in Bug 14168. As the bug is very
old, testers have not been found, and I do not have the case where the
indicated signal is less than -70 dBm.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Stable <stable@kernel.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 22 insertions, 5 deletions

diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c
index c5a5e788f25f..1e0be14d10d4 100644
--- a/drivers/net/wireless/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c
@@ -869,23 +869,35 @@ static void rtl8187_work(struct work_struct *work)
         /* The RTL8187 returns the retry count through register 0xFFFA. In
          * addition, it appears to be a cumulative retry count, not the
          * value for the current TX packet. When multiple TX entries are
-         * queued, the retry count will be valid for the last one in the queue.
-         * The "error" should not matter for purposes of rate setting. */
+         * waiting in the queue, the retry count will be the total for all.
+         * The "error" may matter for purposes of rate setting, but there is
+         * no other choice with this hardware.
+         */
         struct rtl8187_priv *priv = container_of(work, struct rtl8187_priv,
                                     work.work);
         struct ieee80211_tx_info *info;
         struct ieee80211_hw *dev = priv->dev;
         static u16 retry;
         u16 tmp;
+        u16 avg_retry;
+        int length;
 
         mutex_lock(&priv->conf_mutex);
         tmp = rtl818x_ioread16(priv, (__le16 *)0xFFFA);
+        length = skb_queue_len(&priv->b_tx_status.queue);
+        if (unlikely(!length))
+                length = 1;
+        if (unlikely(tmp < retry))
+                tmp = retry;
+        avg_retry = (tmp - retry) / length;
         while (skb_queue_len(&priv->b_tx_status.queue) > 0) {
                 struct sk_buff *old_skb;
 
                 old_skb = skb_dequeue(&priv->b_tx_status.queue);
                 info = IEEE80211_SKB_CB(old_skb);
-                info->status.rates[0].count = tmp - retry + 1;
+                info->status.rates[0].count = avg_retry + 1;
+                if (info->status.rates[0].count > RETRY_COUNT)
+                        info->flags &= ~IEEE80211_TX_STAT_ACK;
                 ieee80211_tx_status_irqsafe(dev, old_skb);
         }
         retry = tmp;
@@ -931,8 +943,8 @@ static int rtl8187_start(struct ieee80211_hw *dev)
                 rtl818x_iowrite32(priv, &priv->map->TX_CONF,
                                   RTL818X_TX_CONF_HW_SEQNUM |
                                   RTL818X_TX_CONF_DISREQQSIZE |
-                                  (7 << 8  /* short retry limit */) |
-                                  (7 << 0  /* long retry limit */) |
+                                  (RETRY_COUNT << 8  /* short retry limit */) |
+                                  (RETRY_COUNT << 0  /* long retry limit */) |
                                   (7 << 21 /* MAX TX DMA */));
                 rtl8187_init_urbs(dev);
                 rtl8187b_init_status_urb(dev);
@@ -1376,6 +1388,9 @@ static int __devinit rtl8187_probe(struct usb_interface *intf,
         dev->flags = IEEE80211_HW_HOST_BROADCAST_PS_BUFFERING |
                      IEEE80211_HW_SIGNAL_DBM |
                      IEEE80211_HW_RX_INCLUDES_FCS;
+        /* Initialize rate-control variables */
+        dev->max_rates = 1;
+        dev->max_rate_tries = RETRY_COUNT;
 
         eeprom.data = dev;
         eeprom.register_read = rtl8187_eeprom_register_read;
diff --git a/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h b/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h
index 0d7b1423f77b..f1cc90751dbf 100644
--- a/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h
+++ b/drivers/net/wireless/rtl818x/rtl8187/rtl8187.h
@@ -35,6 +35,8 @@
 #define RFKILL_MASK_8187_89_97  0x2
 #define RFKILL_MASK_8198        0x4
 
+#define RETRY_COUNT             7
+
 struct rtl8187_rx_info {
         struct urb *urb;
         struct ieee80211_hw *dev;