Re: [PATCH 4/4] cfg80211: add cellular base station regulatory hint support

["Luis R. Rodriguez" <rodrigue@qca.qualcomm.com>]

FWIW, here's the delta I plan on adding that adds a device
count for number of devices that support the base station
hints and disregards the hints unless the core has 1 device
that supports this. I'll roll this into a new series and
later send ath5k / ath9k patches separately as I see now
that cfg80211 changes go through you and driver updates
through linville.

diff --git a/net/wireless/core.c b/net/wireless/core.c
index e13365f..153f7dc 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -537,6 +537,7 @@ int wiphy_register(struct wiphy *wiphy)
 	}
 
 	/* set up regulatory info */
+	wiphy_regulatory_register(wiphy);
 	regulatory_update(wiphy, NL80211_REGDOM_SET_BY_CORE);
 
 	list_add_rcu(&rdev->list, &cfg80211_rdev_list);
diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 3644159..05af62d 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -97,9 +97,16 @@ const struct ieee80211_regdomain *cfg80211_regdomain;
  *     - cfg80211_world_regdom
  *     - cfg80211_regdom
  *     - last_request
+ *     - reg_num_devs_support_basehint
  */
 static DEFINE_MUTEX(reg_mutex);
 
+/*
+ * Number of devices that registered to the core
+ * that support cellular base station regulatory hints
+ */
+static int reg_num_devs_support_basehint;
+
 static inline void assert_reg_lock(void)
 {
 	lockdep_assert_held(&reg_mutex);
@@ -934,6 +941,9 @@ bool reg_last_request_cell_base(void)
 /* Core specific check */
 static int reg_ignore_cell_hint(struct regulatory_request *pending_request)
 {
+	if (!reg_num_devs_support_basehint)
+		return -EOPNOTSUPP;
+
 	if (reg_request_cell_base(last_request)) {
 		if (!regdom_changes(pending_request->alpha2))
 			return -EALREADY;
@@ -2365,6 +2375,18 @@ int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 }
 #endif /* CONFIG_HOTPLUG */
 
+void wiphy_regulatory_register(struct wiphy *wiphy)
+{
+	assert_cfg80211_lock();
+
+	mutex_lock(&reg_mutex);
+
+	if (!reg_dev_ignore_cell_hint(wiphy))
+		reg_num_devs_support_basehint++;
+
+	mutex_unlock(&reg_mutex);
+}
+
 /* Caller must hold cfg80211_mutex */
 void reg_device_remove(struct wiphy *wiphy)
 {
@@ -2374,6 +2396,9 @@ void reg_device_remove(struct wiphy *wiphy)
 
 	mutex_lock(&reg_mutex);
 
+	if (!reg_dev_ignore_cell_hint(wiphy))
+		reg_num_devs_support_basehint--;
+
 	kfree(wiphy->regd);
 
 	if (last_request)
diff --git a/net/wireless/reg.h b/net/wireless/reg.h
index ba1097e..519492f 100644
--- a/net/wireless/reg.h
+++ b/net/wireless/reg.h
@@ -26,6 +26,7 @@ int regulatory_hint_user(const char *alpha2,
 			 enum nl80211_user_reg_hint_type user_reg_hint_type);
 
 int reg_device_uevent(struct device *dev, struct kobj_uevent_env *env);
+void wiphy_regulatory_register(struct wiphy *wiphy);
 void reg_device_remove(struct wiphy *wiphy);
 
 int __init regulatory_init(void);