iwlwifi: support truly passive scanning

If passive scanning is requested we should not ask the
microcode to do active scanning after detecting traffic
on a channel -- that should only be used when an active
scan is requested but some channels are marked passive.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl3945-base.c b/drivers/net/wireless/iwlwifi/iwl3945-base.c
index 4df9b4b..c15d0cf 100644
--- a/drivers/net/wireless/iwlwifi/iwl3945-base.c
+++ b/drivers/net/wireless/iwlwifi/iwl3945-base.c
@@ -3078,7 +3078,12 @@
 		band = IEEE80211_BAND_2GHZ;
 	} else if (priv->scan_bands & BIT(IEEE80211_BAND_5GHZ)) {
 		scan->tx_cmd.rate = IWL_RATE_6M_PLCP;
-		scan->good_CRC_th = IWL_GOOD_CRC_TH;
+		/*
+		 * If active scaning is requested but a certain channel
+		 * is marked passive, we can do active scanning if we
+		 * detect transmissions.
+		 */
+		scan->good_CRC_th = is_active ? IWL_GOOD_CRC_TH : 0;
 		band = IEEE80211_BAND_5GHZ;
 	} else {
 		IWL_WARN(priv, "Invalid scan band count\n");