iwl3945: place CCK rates in front of OFDM for supported rates

The patch fixes association failure (reason = 18) bug by arranging CCK
rates before OFDM rates. This patch will register with mac80211 the
modified rate arrangement with CCK rate first. Change rate scale algorithm
also to deal with rate change. Fix Txpower and rate Table commands to be
constructed correctly after rearrangement.

Signed-off-by: Mohamed Abbas <mabbas@linux.intel.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 48 insertions, 8 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
index 262ab0b55824..c48b1b537d2b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -71,19 +71,19 @@ struct iwl_rate_scale_priv {
 };
 
 static s32 iwl_expected_tpt_g[IWL_RATE_COUNT] = {
-	0, 0, 76, 104, 130, 168, 191, 202, 7, 13, 35, 58
+	7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
 };
 
 static s32 iwl_expected_tpt_g_prot[IWL_RATE_COUNT] = {
-	0, 0, 0, 80, 93, 113, 123, 125, 7, 13, 35, 58
+	7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
 };
 
 static s32 iwl_expected_tpt_a[IWL_RATE_COUNT] = {
-	40, 57, 72, 98, 121, 154, 177, 186, 0, 0, 0, 0
+	0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
 };
 
 static s32 iwl_expected_tpt_b[IWL_RATE_COUNT] = {
-	0, 0, 0, 0, 0, 0, 0, 0, 7, 13, 35, 58
+	7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
 };
 
 struct iwl_tpt_entry {
@@ -350,6 +350,10 @@ static void rs_rate_init(void *priv_rate, void *priv_sta,
 
 	sta->last_txrate = sta->txrate;
 
+	/* For MODE_IEEE80211A mode it start at IWL_FIRST_OFDM_RATE */
+        if (local->hw.conf.phymode == MODE_IEEE80211A)
+                sta->last_txrate += IWL_FIRST_OFDM_RATE;
+
 	IWL_DEBUG_RATE("leave\n");
 }
 
@@ -417,6 +421,33 @@ static void rs_free_sta(void *priv, void *priv_sta)
 	IWL_DEBUG_RATE("leave\n");
 }
 
+
+/*
+ * get ieee prev rate from rate scale table.
+ * for A and B mode we need to overright prev
+ * value
+ */
+static int rs_adjust_next_rate(struct iwl_priv *priv, int rate)
+{
+	int next_rate = iwl_get_prev_ieee_rate(rate);
+
+	switch (priv->phymode) {
+	case MODE_IEEE80211A:
+		if (rate == IWL_RATE_12M_INDEX)
+			next_rate = IWL_RATE_9M_INDEX;
+		else if (rate == IWL_RATE_6M_INDEX)
+			next_rate = IWL_RATE_6M_INDEX;
+		break;
+	case MODE_IEEE80211B:
+		if (rate == IWL_RATE_11M_INDEX_TABLE)
+			next_rate = IWL_RATE_5M_INDEX_TABLE;
+		break;
+	default:
+		break;
+	}
+
+	return next_rate;
+}
 /**
  * rs_tx_status - Update rate control values based on Tx results
  *
@@ -479,7 +510,8 @@ static void rs_tx_status(void *priv_rate,
 			last_index = scale_rate_index;
 		} else {
 			current_count = priv->retry_rate;
-			last_index = iwl_get_prev_ieee_rate(scale_rate_index);
+			last_index = rs_adjust_next_rate(priv,
+							 scale_rate_index);
 		}
 
 		/* Update this rate accounting for as many retries
@@ -494,9 +526,10 @@ static void rs_tx_status(void *priv_rate,
 
 		if (retries)
 			scale_rate_index =
-			    iwl_get_prev_ieee_rate(scale_rate_index);
+			    rs_adjust_next_rate(priv, scale_rate_index);
 	}
 
+
 	/* Update the last index window with success/failure based on ACK */
 	IWL_DEBUG_RATE("Update rate %d with %s.\n",
 		       last_index,
@@ -672,7 +705,10 @@ static struct ieee80211_rate *rs_get_rate(void *priv_rate,
 	}
 
 	rate_mask = sta->supp_rates;
-	index = min(sta->txrate & 0xffff, IWL_RATE_COUNT - 1);
+	index = min(sta->last_txrate & 0xffff, IWL_RATE_COUNT - 1);
+
+	if (priv->phymode == (u8) MODE_IEEE80211A)
+		rate_mask = rate_mask << IWL_FIRST_OFDM_RATE;
 
 	rs_priv = (void *)sta->rate_ctrl_priv;
 
@@ -801,7 +837,11 @@ static struct ieee80211_rate *rs_get_rate(void *priv_rate,
  out:
 
 	sta->last_txrate = index;
-	sta->txrate = sta->last_txrate;
+	if (priv->phymode == (u8) MODE_IEEE80211A)
+		sta->txrate = sta->last_txrate - IWL_FIRST_OFDM_RATE;
+	else
+		sta->txrate = sta->last_txrate;
+
 	sta_info_put(sta);
 
 	IWL_DEBUG_RATE("leave: %d\n", index);