[4/4] cfg80211: Fix regulatory bug with multiple cards and delays

Commit Message

Luis Rodriguez Nov. 18, 2010, 5:55 a.m. UTC

None

Patch

diff --git a/include/net/regulatory.h b/include/net/regulatory.h
index 9e103a4..356d6e3 100644
--- a/include/net/regulatory.h
+++ b/include/net/regulatory.h
@@ -43,6 +43,12 @@  enum environment_cap {
  * @intersect: indicates whether the wireless core should intersect
  * 	the requested regulatory domain with the presently set regulatory
  * 	domain.
+ * @processed: indicates whether or not this requests has already been
+ *	processed. When the last request is processed it means that the
+ *	currently regulatory domain set on cfg80211 is updated from
+ *	CRDA and can be used by other regulatory requests. When a
+ *	the last request is not yet processed we must yield until it
+ *	is processed before processing any new requests.
  * @country_ie_checksum: checksum of the last processed and accepted
  * 	country IE
  * @country_ie_env: lets us know if the AP is telling us we are outdoor,
@@ -54,6 +60,7 @@  struct regulatory_request {
 	enum nl80211_reg_initiator initiator;
 	char alpha2[2];
 	bool intersect;
+	bool processed;
 	enum environment_cap country_ie_env;
 	struct list_head list;
 };
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index b522c46..bc14caa 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1320,6 +1320,21 @@  static int ignore_request(struct wiphy *wiphy,
 	return -EINVAL;
 }
 
+static void reg_set_request_processed(void)
+{
+	bool need_more_processing = false;
+
+	last_request->processed = true;
+
+	spin_lock(&reg_requests_lock);
+	if (!list_empty(&reg_requests_list))
+		need_more_processing = true;
+	spin_unlock(&reg_requests_lock);
+
+	if (need_more_processing)
+		schedule_work(&reg_work);
+}
+
 /**
  * __regulatory_hint - hint to the wireless core a regulatory domain
  * @wiphy: if the hint comes from country information from an AP, this
@@ -1395,8 +1410,10 @@  new_request:
 		 * have applied the requested regulatory domain before we just
 		 * inform userspace we have processed the request
 		 */
-		if (r == -EALREADY)
+		if (r == -EALREADY) {
 			nl80211_send_reg_change_event(last_request);
+			reg_set_request_processed();
+		}
 		return r;
 	}
 
@@ -1428,7 +1445,11 @@  static void reg_process_hint(struct regulatory_request *reg_request)
 		wiphy_update_regulatory(wiphy, initiator);
 }
 
-/* Processes regulatory hints, this is all the NL80211_REGDOM_SET_BY_* */
+/*
+ * Processes regulatory hints, this is all the NL80211_REGDOM_SET_BY_*
+ * Regulatory hints come on a first come first serve basis and we
+ * must process each one atomically.
+ */
 static void reg_process_pending_hints(void)
 {
 	struct regulatory_request *reg_request;
@@ -1436,19 +1457,30 @@  static void reg_process_pending_hints(void)
 	mutex_lock(&cfg80211_mutex);
 	mutex_lock(&reg_mutex);
 
+	/* When last_request->processed becomes true this will be rescheduled */
+	if (last_request && !last_request->processed) {
+		REG_DBG_PRINT("Pending regulatory request, waiting "
+			      "for it to be processed...");
+		goto out;
+	}
+
 	spin_lock(&reg_requests_lock);
-	while (!list_empty(&reg_requests_list)) {
-		reg_request = list_first_entry(&reg_requests_list,
-					       struct regulatory_request,
-					       list);
-		list_del_init(&reg_request->list);
 
+	if (list_empty(&reg_requests_list)) {
 		spin_unlock(&reg_requests_lock);
-		reg_process_hint(reg_request);
-		spin_lock(&reg_requests_lock);
+		goto out;
 	}
+
+	reg_request = list_first_entry(&reg_requests_list,
+				       struct regulatory_request,
+				       list);
+	list_del_init(&reg_request->list);
+
 	spin_unlock(&reg_requests_lock);
 
+	reg_process_hint(reg_request);
+
+out:
 	mutex_unlock(&reg_mutex);
 	mutex_unlock(&cfg80211_mutex);
 }
@@ -2057,6 +2089,8 @@  int set_regdom(const struct ieee80211_regdomain *rd)
 
 	nl80211_send_reg_change_event(last_request);
 
+	reg_set_request_processed();
+
 	mutex_unlock(&reg_mutex);
 
 	return r;