iwlwifi: check short GI support per-station rather than globally

Short guard interval support is a local per-station parameter not a global
per-NIC parameter.  (mac80211 will correctly remove SGI support from station
capabilities if the BSS does not permit it).  This patch removes the short GI
support bitfield from the global iwl_ht_info struct and properly uses
per-station HT capabilities during rate selection.

Signed-off-by: Daniel C Halperin <daniel.c.halperin@intel.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 15 insertions, 54 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 551c4ba3f178..3b1bbc394a49 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -1225,18 +1225,6 @@ static int rs_switch_to_mimo2(struct iwl_priv *priv,
         else
                 tbl->is_ht40 = 0;
 
-        /* FIXME: - don't toggle SGI here
-        if (tbl->is_ht40) {
-                if (priv->current_ht_config.sgf & HT_SHORT_GI_40MHZ_ONLY)
-                        tbl->is_SGI = 1;
-                else
-                        tbl->is_SGI = 0;
-        } else if (priv->current_ht_config.sgf & HT_SHORT_GI_20MHZ_ONLY)
-                tbl->is_SGI = 1;
-        else
-                tbl->is_SGI = 0;
-        */
-
         rs_set_expected_tpt_table(lq_sta, tbl);
 
         rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
@@ -1291,18 +1279,6 @@ static int rs_switch_to_mimo3(struct iwl_priv *priv,
         else
                 tbl->is_ht40 = 0;
 
-        /* FIXME: - don't toggle SGI here
-        if (tbl->is_ht40) {
-                if (priv->current_ht_config.sgf & HT_SHORT_GI_40MHZ_ONLY)
-                        tbl->is_SGI = 1;
-                else
-                        tbl->is_SGI = 0;
-        } else if (priv->current_ht_config.sgf & HT_SHORT_GI_20MHZ_ONLY)
-                tbl->is_SGI = 1;
-        else
-                tbl->is_SGI = 0;
-        */
-
         rs_set_expected_tpt_table(lq_sta, tbl);
 
         rate = rs_get_best_rate(priv, lq_sta, tbl, rate_mask, index);
@@ -1350,18 +1326,6 @@ static int rs_switch_to_siso(struct iwl_priv *priv,
         else
                 tbl->is_ht40 = 0;
 
-        /* FIXME: - don't toggle SGI here
-        if (tbl->is_ht40) {
-                if (priv->current_ht_config.sgf & HT_SHORT_GI_40MHZ_ONLY)
-                        tbl->is_SGI = 1;
-                else
-                        tbl->is_SGI = 0;
-        } else if (priv->current_ht_config.sgf & HT_SHORT_GI_20MHZ_ONLY)
-                tbl->is_SGI = 1;
-        else
-                tbl->is_SGI = 0;
-        */
-
         if (is_green)
                 tbl->is_SGI = 0; /*11n spec: no SGI in SISO+Greenfield*/
 
@@ -1530,6 +1494,7 @@ static int rs_move_siso_to_other(struct iwl_priv *priv,
         struct iwl_scale_tbl_info *search_tbl =
                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
         struct iwl_rate_scale_data *window = &(tbl->win[index]);
+        struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
         u8 start_action = tbl->action;
@@ -1589,13 +1554,11 @@ static int rs_move_siso_to_other(struct iwl_priv *priv,
                                 goto out;
                         break;
                 case IWL_SISO_SWITCH_GI:
-                        if (!tbl->is_ht40 &&
-                                !(priv->current_ht_config.sgf &
-                                                HT_SHORT_GI_20MHZ))
+                        if (!tbl->is_ht40 && !(ht_cap->cap &
+                                                IEEE80211_HT_CAP_SGI_20))
                                 break;
-                        if (tbl->is_ht40 &&
-                                !(priv->current_ht_config.sgf &
-                                                HT_SHORT_GI_40MHZ))
+                        if (tbl->is_ht40 && !(ht_cap->cap &
+                                                IEEE80211_HT_CAP_SGI_40))
                                 break;
 
                         IWL_DEBUG_RATE(priv, "LQ: SISO toggle SGI/NGI\n");
@@ -1669,6 +1632,7 @@ static int rs_move_mimo2_to_other(struct iwl_priv *priv,
         struct iwl_scale_tbl_info *search_tbl =
                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
         struct iwl_rate_scale_data *window = &(tbl->win[index]);
+        struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
         u8 start_action = tbl->action;
@@ -1729,13 +1693,11 @@ static int rs_move_mimo2_to_other(struct iwl_priv *priv,
                         break;
 
                 case IWL_MIMO2_SWITCH_GI:
-                        if (!tbl->is_ht40 &&
-                                !(priv->current_ht_config.sgf &
-                                                HT_SHORT_GI_20MHZ))
+                        if (!tbl->is_ht40 && !(ht_cap->cap &
+                                                IEEE80211_HT_CAP_SGI_20))
                                 break;
-                        if (tbl->is_ht40 &&
-                                !(priv->current_ht_config.sgf &
-                                                HT_SHORT_GI_40MHZ))
+                        if (tbl->is_ht40 && !(ht_cap->cap &
+                                                IEEE80211_HT_CAP_SGI_40))
                                 break;
 
                         IWL_DEBUG_RATE(priv, "LQ: MIMO2 toggle SGI/NGI\n");
@@ -1811,6 +1773,7 @@ static int rs_move_mimo3_to_other(struct iwl_priv *priv,
         struct iwl_scale_tbl_info *search_tbl =
                                 &(lq_sta->lq_info[(1 - lq_sta->active_tbl)]);
         struct iwl_rate_scale_data *window = &(tbl->win[index]);
+        struct ieee80211_sta_ht_cap *ht_cap = &sta->ht_cap;
         u32 sz = (sizeof(struct iwl_scale_tbl_info) -
                   (sizeof(struct iwl_rate_scale_data) * IWL_RATE_COUNT));
         u8 start_action = tbl->action;
@@ -1893,13 +1856,11 @@ static int rs_move_mimo3_to_other(struct iwl_priv *priv,
                         break;
 
                 case IWL_MIMO3_SWITCH_GI:
-                        if (!tbl->is_ht40 &&
-                                !(priv->current_ht_config.sgf &
-                                                HT_SHORT_GI_20MHZ))
+                        if (!tbl->is_ht40 && !(ht_cap->cap &
+                                                IEEE80211_HT_CAP_SGI_20))
                                 break;
-                        if (tbl->is_ht40 &&
-                                !(priv->current_ht_config.sgf &
-                                                HT_SHORT_GI_40MHZ))
+                        if (tbl->is_ht40 && !(ht_cap->cap &
+                                                IEEE80211_HT_CAP_SGI_40))
                                 break;
 
                         IWL_DEBUG_RATE(priv, "LQ: MIMO3 toggle SGI/NGI\n");