cfg80211: set initial monitor channel

Implements behaviour seen in mac80211. A running
monitor always has a channel - even before
.set_channel. This way we won't break current
behaviour.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 1b5daa73b3a9..580551e9caba 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -717,6 +717,35 @@ static struct device_type wiphy_type = {
         .name   = "wlan",
 };
 
+static struct ieee80211_channel *
+cfg80211_get_any_chan(struct cfg80211_registered_device *rdev)
+{
+        struct ieee80211_supported_band *sband;
+        int i;
+
+        for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
+                sband = rdev->wiphy.bands[i];
+                if (sband && sband->n_channels > 0)
+                        return &sband->channels[0];
+        }
+
+        return NULL;
+}
+
+static void cfg80211_init_mon_chan(struct cfg80211_registered_device *rdev)
+{
+        struct ieee80211_channel *chan;
+
+        chan = cfg80211_get_any_chan(rdev);
+        if (WARN_ON(!chan))
+                return;
+
+        mutex_lock(&rdev->devlist_mtx);
+        WARN_ON(cfg80211_set_monitor_channel(rdev, chan->center_freq,
+                                             NL80211_CHAN_NO_HT));
+        mutex_unlock(&rdev->devlist_mtx);
+}
+
 void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
                                enum nl80211_iftype iftype, int num)
 {
@@ -737,6 +766,8 @@ void cfg80211_update_iface_num(struct cfg80211_registered_device *rdev,
                 if (!has_monitors_only_new) {
                         rdev->monitor_channel = NULL;
                         rdev->monitor_channel_type = NL80211_CHAN_NO_HT;
+                } else {
+                        cfg80211_init_mon_chan(rdev);
                 }
         }
 }