iwlwifi: allow user to set max rate

allow user to set max rate through #iwconfig <inteface> rate XXX.
mac80211 will try to force this if user set it, but driver is not
in sync which cause mac80211 to report wrong current rate. This
patch will check if max rate is set and force it in rate scaling

Signed-off-by: mohamed abbas <mohamed.abbas@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
index 25b4356fcc1c..044abf734eb6 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-rs.c
@@ -651,6 +651,7 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
         u16 fc;
         u16 rate_mask = 0;
+        s8 max_rate_idx = -1;
         struct iwl_priv *priv = (struct iwl_priv *)priv_r;
         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 
@@ -675,6 +676,13 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
                 return;
         }
 
+        /* get user max rate if set */
+        max_rate_idx = txrc->max_rate_idx;
+        if ((sband->band == IEEE80211_BAND_5GHZ) && (max_rate_idx != -1))
+                max_rate_idx += IWL_FIRST_OFDM_RATE;
+        if ((max_rate_idx < 0) || (max_rate_idx >= IWL_RATE_COUNT))
+                max_rate_idx = -1;
+
         index = min(rs_sta->last_txrate_idx & 0xffff, IWL_RATE_COUNT_3945 - 1);
 
         if (sband->band == IEEE80211_BAND_5GHZ)
@@ -706,6 +714,12 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
                 rs_sta->start_rate = IWL_RATE_INVALID;
         }
 
+        /* force user max rate if set by user */
+        if ((max_rate_idx != -1) && (max_rate_idx < index)) {
+                if (rate_mask & (1 << max_rate_idx))
+                        index = max_rate_idx;
+        }
+
         window = &(rs_sta->win[index]);
 
         fail_count = window->counter - window->success_counter;
@@ -732,6 +746,10 @@ static void rs_get_rate(void *priv_r, struct ieee80211_sta *sta,
         low = high_low & 0xff;
         high = (high_low >> 8) & 0xff;
 
+        /* If user set max rate, dont allow higher than user constrain */
+        if ((max_rate_idx != -1) && (max_rate_idx < high))
+                high = IWL_RATE_INVALID;
+
         if (low != IWL_RATE_INVALID)
                 low_tpt = rs_sta->win[low].average_tpt;