iwlwifi: revert to active table when rate is not valid

When performing rate scaling, if detected that the new rate
index is invalid, clear the search_better_tbl flag
so it will not be stuck in the loop.

Since the search table is already set up in uCode,
we need to empty out the the search table;
revert back to the "active" rate and throughput info.
Also pass the "active" table setup to uCode to make
sure the rate scale is functioning correctly.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 32 insertions, 5 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 63280411fd58..40207dac6db5 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -2003,6 +2003,25 @@ static void rs_stay_in_table(struct iwl_lq_sta *lq_sta)
 }
 
 /*
+ * setup rate table in uCode
+ * return rate_n_flags as used in the table
+ */
+static u32 rs_update_rate_tbl(struct iwl_priv *priv,
+                                struct iwl_lq_sta *lq_sta,
+                                struct iwl_scale_tbl_info *tbl,
+                                int index, u8 is_green)
+{
+        u32 rate;
+
+        /* Update uCode's rate table. */
+        rate = rate_n_flags_from_tbl(priv, tbl, index, is_green);
+        rs_fill_link_cmd(priv, lq_sta, rate);
+        iwl_send_lq_cmd(priv, &lq_sta->lq, CMD_ASYNC);
+
+        return rate;
+}
+
+/*
  * Do rate scaling and search for new modulation mode.
  */
 static void rs_rate_scale_perform(struct iwl_priv *priv,
@@ -2098,6 +2117,16 @@ static void rs_rate_scale_perform(struct iwl_priv *priv,
 
         if (!((1 << index) & rate_scale_index_msk)) {
                 IWL_ERR(priv, "Current Rate is not valid\n");
+                if (lq_sta->search_better_tbl) {
+                        /* revert to active table if search table is not valid*/
+                        tbl->lq_type = LQ_NONE;
+                        lq_sta->search_better_tbl = 0;
+                        tbl = &(lq_sta->lq_info[lq_sta->active_tbl]);
+                        /* get "active" rate info */
+                        index = iwl_hwrate_to_plcp_idx(tbl->current_rate);
+                        rate = rs_update_rate_tbl(priv, lq_sta,
+                                                  tbl, index, is_green);
+                }
                 return;
         }
 
@@ -2308,11 +2337,9 @@ static void rs_rate_scale_perform(struct iwl_priv *priv,
 
 lq_update:
         /* Replace uCode's rate table for the destination station. */
-        if (update_lq) {
-                rate = rate_n_flags_from_tbl(priv, tbl, index, is_green);
-                rs_fill_link_cmd(priv, lq_sta, rate);
-                iwl_send_lq_cmd(priv, &lq_sta->lq, CMD_ASYNC);
-        }
+        if (update_lq)
+                rate = rs_update_rate_tbl(priv, lq_sta,
+                                          tbl, index, is_green);
 
         /* Should we stay with this modulation mode, or search for a new one? */
         rs_stay_in_table(lq_sta);