1 files changed, 56 insertions, 0 deletions
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 5946450c5406..8659d5cee2a6 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -490,6 +490,62 @@ static bool cfg80211_chandef_dfs_available(struct wiphy *wiphy,
 	return r;
 }
 
+static unsigned int cfg80211_get_chans_dfs_cac_time(struct wiphy *wiphy,
+						    u32 center_freq,
+						    u32 bandwidth)
+{
+	struct ieee80211_channel *c;
+	u32 start_freq, end_freq, freq;
+	unsigned int dfs_cac_ms = 0;
+
+	start_freq = cfg80211_get_start_freq(center_freq, bandwidth);
+	end_freq = cfg80211_get_end_freq(center_freq, bandwidth);
+
+	for (freq = start_freq; freq <= end_freq; freq += 20) {
+		c = ieee80211_get_channel(wiphy, freq);
+		if (!c)
+			return 0;
+
+		if (c->flags & IEEE80211_CHAN_DISABLED)
+			return 0;
+
+		if (!(c->flags & IEEE80211_CHAN_RADAR))
+			continue;
+
+		if (c->dfs_cac_ms > dfs_cac_ms)
+			dfs_cac_ms = c->dfs_cac_ms;
+	}
+
+	return dfs_cac_ms;
+}
+
+unsigned int
+cfg80211_chandef_dfs_cac_time(struct wiphy *wiphy,
+			      const struct cfg80211_chan_def *chandef)
+{
+	int width;
+	unsigned int t1 = 0, t2 = 0;
+
+	if (WARN_ON(!cfg80211_chandef_valid(chandef)))
+		return 0;
+
+	width = cfg80211_chandef_get_width(chandef);
+	if (width < 0)
+		return 0;
+
+	t1 = cfg80211_get_chans_dfs_cac_time(wiphy,
+					     chandef->center_freq1,
+					     width);
+
+	if (!chandef->center_freq2)
+		return t1;
+
+	t2 = cfg80211_get_chans_dfs_cac_time(wiphy,
+					     chandef->center_freq2,
+					     width);
+
+	return max(t1, t2);
+}
 
 static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy,
 					u32 center_freq, u32 bandwidth,