iwlwifi: fix IBSS beaconing

My previous patch to clean up all RXON handling
inadvertently broke IBSS because it failed to
take into account that unlike in AP mode, IBSS
requires beacons to be sent only after setting
the RXON assoc.

Fix this, clean up the code a bit, improve the
error checking around this, and also react to
beacon changes in IBSS mode from mac80211.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/iwlwifi/iwl-agn-rxon.c

@@ -72,6 +72,18 @@ static int iwlagn_disable_pan(struct iwl_priv *priv,
 	return ret;
 }
 
+static int iwlagn_update_beacon(struct iwl_priv *priv,
+				struct ieee80211_vif *vif)
+{
+	lockdep_assert_held(&priv->mutex);
+
+	dev_kfree_skb(priv->beacon_skb);
+	priv->beacon_skb = ieee80211_beacon_get(priv->hw, vif);
+	if (!priv->beacon_skb)
+		return -ENOMEM;
+	return iwlagn_send_beacon_cmd(priv);
+}
+
 /**
  * iwlagn_commit_rxon - commit staging_rxon to hardware
  *
@@ -201,17 +213,19 @@ int iwlagn_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 	}
 
 	if (new_assoc) {
-		if (ctx->vif && (ctx->vif->type == NL80211_IFTYPE_AP ||
-				 ctx->vif->type == NL80211_IFTYPE_ADHOC)) {
-			/*
-			 * We'll run into this code path when beaconing is
-			 * enabled, but then we also need to send the beacon
-			 * to the device.
-			 */
-			dev_kfree_skb(priv->beacon_skb);
-			priv->beacon_skb = ieee80211_beacon_get(priv->hw,
-								ctx->vif);
-			iwlagn_send_beacon_cmd(priv);
+		/*
+		 * We'll run into this code path when beaconing is
+		 * enabled, but then we also need to send the beacon
+		 * to the device.
+		 */
+		if (ctx->vif && (ctx->vif->type == NL80211_IFTYPE_AP)) {
+			ret = iwlagn_update_beacon(priv, ctx->vif);
+			if (ret) {
+				IWL_ERR(priv,
+					"Error sending required beacon (%d)!\n",
+					ret);
+				return ret;
+			}
 		}
 
 		priv->start_calib = 0;
@@ -228,6 +242,11 @@ int iwlagn_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 			return ret;
 		}
 		memcpy(active, &ctx->staging, sizeof(*active));
+
+		/* IBSS beacon needs to be sent after setting assoc */
+		if (ctx->vif && (ctx->vif->type == NL80211_IFTYPE_ADHOC))
+			if (iwlagn_update_beacon(priv, ctx->vif))
+				IWL_ERR(priv, "Error sending IBSS beacon\n");
 	}
 
 	iwl_print_rx_config_cmd(priv, ctx);
@@ -558,5 +577,11 @@ void iwlagn_bss_info_changed(struct ieee80211_hw *hw,
 				bss_conf->bssid);
 	}
 
+	if (changes & BSS_CHANGED_BEACON && vif->type == NL80211_IFTYPE_ADHOC &&
+	    priv->beacon_ctx) {
+		if (iwlagn_update_beacon(priv, vif))
+			IWL_ERR(priv, "Error sending IBSS beacon\n");
+	}
+
 	mutex_unlock(&priv->mutex);
 }