cfg80211: warn when wiphy_apply_custom_regulatory() does nothing

Device drivers using wiphy_apply_custom_regulatory() want some
regulatory settings applied to their wiphy, if no bands were
configured on the wiphy then something went wrong.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/net/wireless/reg.c b/net/wireless/reg.c
index 8d176a8010ba..df0ced9405d3 100644
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -1344,13 +1344,22 @@ void wiphy_apply_custom_regulatory(struct wiphy *wiphy,
                                    const struct ieee80211_regdomain *regd)
 {
         enum ieee80211_band band;
+        unsigned int bands_set = 0;
 
         mutex_lock(&cfg80211_mutex);
         for (band = 0; band < IEEE80211_NUM_BANDS; band++) {
-                if (wiphy->bands[band])
-                        handle_band_custom(wiphy, band, regd);
+                if (!wiphy->bands[band])
+                        continue;
+                handle_band_custom(wiphy, band, regd);
+                bands_set++;
         }
         mutex_unlock(&cfg80211_mutex);
+
+        /*
+         * no point in calling this if it won't have any effect
+         * on your device's supportd bands.
+         */
+        WARN_ON(!bands_set);
 }
 EXPORT_SYMBOL(wiphy_apply_custom_regulatory);