iwlagn: use proper good CRC threshold behaviour

New microcode versions use the good CRC threshold
field differently, as a flag, and in that case we
should set it to 1/0 instead of 1/65535 for an
active/passive scan.

The new behaviour is advertised by the uCode with
a feature flag.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>

3 files changed, 18 insertions, 4 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
index 75e1035330be..7fe9e0f17b1e 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-lib.c
@@ -1294,9 +1294,17 @@ int iwlagn_request_scan(struct iwl_priv *priv, struct ieee80211_vif *vif)
          * mean we never reach it, but at the same time work around
          * the aforementioned issue. Thus use IWL_GOOD_CRC_TH_NEVER
          * here instead of IWL_GOOD_CRC_TH_DISABLED.
+         *
+         * This was fixed in later versions along with some other
+         * scan changes, and the threshold behaves as a flag in those
+         * versions.
          */
-        scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
-                                        IWL_GOOD_CRC_TH_NEVER;
+        if (priv->new_scan_threshold_behaviour)
+                scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+                                                IWL_GOOD_CRC_TH_DISABLED;
+        else
+                scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH_DEFAULT :
+                                                IWL_GOOD_CRC_TH_NEVER;
 
         band = priv->scan_band;
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn.c b/drivers/net/wireless/iwlwifi/iwl-agn.c
index c27147c4d4a7..395d1ade39d3 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn.c
@@ -1716,6 +1716,9 @@ static void iwl_ucode_callback(const struct firmware *ucode_raw, void *context)
                         priv->cfg->base_params->max_event_log_size;
         priv->_agn.inst_errlog_ptr = pieces.inst_errlog_ptr;
 
+        priv->new_scan_threshold_behaviour =
+                !!(ucode_capa.flags & IWL_UCODE_TLV_FLAGS_NEWSCAN);
+
         if (ucode_capa.flags & IWL_UCODE_TLV_FLAGS_PAN) {
                 priv->valid_contexts |= BIT(IWL_RXON_CTX_PAN);
                 priv->sta_key_max_num = STA_KEY_MAX_NUM_PAN;
diff --git a/drivers/net/wireless/iwlwifi/iwl-dev.h b/drivers/net/wireless/iwlwifi/iwl-dev.h
index 197fa742f79a..f098eff263f8 100644
--- a/drivers/net/wireless/iwlwifi/iwl-dev.h
+++ b/drivers/net/wireless/iwlwifi/iwl-dev.h
@@ -547,12 +547,13 @@ enum iwl_ucode_tlv_type {
  * enum iwl_ucode_tlv_flag - ucode API flags
  * @IWL_UCODE_TLV_FLAGS_PAN: This is PAN capable microcode; this previously
  *      was a separate TLV but moved here to save space.
- * @IWL_UCODE_TLV_FLAGS_RESERVED_1: reserved
+ * @IWL_UCODE_TLV_FLAGS_NEWSCAN: new uCode scan behaviour on hidden SSID,
+ *      treats good CRC threshold as a boolean
  * @IWL_UCODE_TLV_FLAGS_MFP: This uCode image supports MFP (802.11w).
  */
 enum iwl_ucode_tlv_flag {
         IWL_UCODE_TLV_FLAGS_PAN         = BIT(0),
-        IWL_UCODE_TLV_FLAGS_RESERVED_1  = BIT(1),
+        IWL_UCODE_TLV_FLAGS_NEWSCAN     = BIT(1),
         IWL_UCODE_TLV_FLAGS_MFP         = BIT(2),
 };
 
@@ -1263,6 +1264,8 @@ struct iwl_priv {
         /* max number of station keys */
         u8 sta_key_max_num;
 
+        bool new_scan_threshold_behaviour;
+
         /* EEPROM MAC addresses */
         struct mac_address addresses[2];