iwlwifi: only add broadcast station once

Currently the broadcast station is added after every RXON command. Change
this to only add the broadcast station when interface is added by mac80211.
With this we need some extra work to ensure broadcast station is always
present since station table is cleared when RXON without ASSOC bit set is
sent. To deal with this we re-add all driver known stations to uCode after
such an RXON command is sent.

We also do some cleanup and remove the various calls to clear the station
table. We now only clear the station table in two scenarios:
- only clear uCode portion of station table when RXON command without ASSOC
bit is sent
- clear uCode and driver portion when interface goes down or is removed.

We need to do this clearing when interface goes down to deal with the
device restart/reconfigure routines which do not remove the interface, but
do add the interface during reconfiguration.

Previously the keys were also cleared when station table in driver is
cleared, this is not done anymore since mac80211 will take care that keys
are set and cleared correctly.

There is a known issue with this change. Associating with different AP
without bringing interface down fails with a firmware error. This is
because of the lack of full station notification support and the later
patches in this series that complete the station notification support will
fix this.

Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>

1 files changed, 85 insertions, 23 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c
index b1aad306efa..312099099ed 100644
--- a/drivers/net/wireless/iwlwifi/iwl-sta.c
+++ b/drivers/net/wireless/iwlwifi/iwl-sta.c
@@ -34,9 +34,6 @@
 #include "iwl-core.h"
 #include "iwl-sta.h"
 
-#define IWL_STA_DRIVER_ACTIVE BIT(0) /* driver entry is active */
-#define IWL_STA_UCODE_ACTIVE  BIT(1) /* ucode entry is active */
-
 u8 iwl_find_station(struct iwl_priv *priv, const u8 *addr)
 {
 	int i;
@@ -495,37 +492,102 @@ out:
 }
 
 /**
- * iwl_clear_stations_table - Clear the driver's station table
- *
- * NOTE:  This does not clear or otherwise alter the device's station table.
+ * iwl_clear_ucode_stations() - clear entire station table driver and/or ucode
+ * @priv:
+ * @force: If set then the uCode station table needs to be cleared here. If
+ *         not set then the uCode station table has already been cleared,
+ *         for example after sending it a RXON command without ASSOC bit
+ *         set, and we just need to change driver state here.
  */
-void iwl_clear_stations_table(struct iwl_priv *priv)
+void iwl_clear_ucode_stations(struct iwl_priv *priv, bool force)
 {
-	unsigned long flags;
 	int i;
+	unsigned long flags_spin;
+	bool cleared = false;
+
+	IWL_DEBUG_INFO(priv, "Clearing ucode stations in driver%s\n",
+			force ? " and ucode" : "");
+
+	if (force) {
+		if (!iwl_is_ready(priv)) {
+			/*
+			 * If device is not ready at this point the station
+			 * table is likely already empty (uCode not ready
+			 * to receive station requests) or will soon be
+			 * due to interface going down.
+			 */
+			IWL_DEBUG_INFO(priv, "Unable to remove stations from device - device not ready\n");
+		} else {
+			iwl_send_cmd_pdu_async(priv, REPLY_REMOVE_ALL_STA, 0, NULL, NULL);
+		}
+	}
 
-	spin_lock_irqsave(&priv->sta_lock, flags);
+	spin_lock_irqsave(&priv->sta_lock, flags_spin);
+	if (force) {
+		IWL_DEBUG_INFO(priv, "Clearing all station information in driver\n");
+		priv->num_stations = 0;
+		memset(priv->stations, 0, sizeof(priv->stations));
+	} else {
+		for (i = 0; i < priv->hw_params.max_stations; i++) {
+			if (priv->stations[i].used & IWL_STA_UCODE_ACTIVE) {
+				IWL_DEBUG_INFO(priv, "Clearing ucode active for station %d \n", i);
+				priv->stations[i].used &= ~IWL_STA_UCODE_ACTIVE;
+				cleared = true;
+			}
+		}
+	}
+	spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
+
+	if (!cleared)
+		IWL_DEBUG_INFO(priv, "No active stations found to be cleared\n");
+}
+EXPORT_SYMBOL(iwl_clear_ucode_stations);
 
-	if (iwl_is_alive(priv) &&
-	   !test_bit(STATUS_EXIT_PENDING, &priv->status) &&
-	   iwl_send_cmd_pdu_async(priv, REPLY_REMOVE_ALL_STA, 0, NULL, NULL))
-		IWL_ERR(priv, "Couldn't clear the station table\n");
+/**
+ * iwl_restore_stations() - Restore driver known stations to device
+ *
+ * All stations considered active by driver, but not present in ucode, is
+ * restored.
+ */
+void iwl_restore_stations(struct iwl_priv *priv)
+{
+	unsigned long flags_spin;
+	int i;
+	bool found = false;
 
-	priv->num_stations = 0;
-	memset(priv->stations, 0, sizeof(priv->stations));
+	if (!iwl_is_ready(priv)) {
+		IWL_DEBUG_INFO(priv, "Not ready yet, not restoring any stations.\n");
+		return;
+	}
 
-	/* clean ucode key table bit map */
-	priv->ucode_key_table = 0;
+	IWL_DEBUG_ASSOC(priv, "Restoring all known stations ... start.\n");
+	spin_lock_irqsave(&priv->sta_lock, flags_spin);
+	for (i = 0; i < priv->hw_params.max_stations; i++) {
+		if ((priv->stations[i].used & IWL_STA_DRIVER_ACTIVE) &&
+			    !(priv->stations[i].used & IWL_STA_UCODE_ACTIVE)) {
+			IWL_DEBUG_ASSOC(priv, "Restoring sta %pM\n",
+					priv->stations[i].sta.sta.addr);
+			priv->stations[i].sta.mode = 0;
+			priv->stations[i].used |= IWL_STA_UCODE_INPROGRESS;
+			found = true;
+		}
+	}
 
-	/* keep track of static keys */
-	for (i = 0; i < WEP_KEYS_MAX ; i++) {
-		if (priv->wep_keys[i].key_size)
-			set_bit(i, &priv->ucode_key_table);
+	for (i = 0; i < priv->hw_params.max_stations; i++) {
+		if ((priv->stations[i].used & IWL_STA_UCODE_INPROGRESS)) {
+			iwl_send_add_sta(priv, &priv->stations[i].sta,
+					 CMD_ASYNC);
+			priv->stations[i].used &= ~IWL_STA_UCODE_INPROGRESS;
+		}
 	}
 
-	spin_unlock_irqrestore(&priv->sta_lock, flags);
+	spin_unlock_irqrestore(&priv->sta_lock, flags_spin);
+	if (!found)
+		IWL_DEBUG_INFO(priv, "Restoring all known stations .... no stations to be restored.\n");
+	else
+		IWL_DEBUG_INFO(priv, "Restoring all known stations .... in progress.\n");
 }
-EXPORT_SYMBOL(iwl_clear_stations_table);
+EXPORT_SYMBOL(iwl_restore_stations);
 
 int iwl_get_free_ucode_key_index(struct iwl_priv *priv)
 {