1 files changed, 20 insertions, 4 deletions

diff --git a/net/wireless/ibss.c b/net/wireless/ibss.c
index 403fe29c024d..9d797df56649 100644
--- a/net/wireless/ibss.c
+++ b/net/wireless/ibss.c
@@ -83,6 +83,8 @@ int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
                          struct cfg80211_cached_keys *connkeys)
 {
         struct wireless_dev *wdev = dev->ieee80211_ptr;
+        struct ieee80211_channel *check_chan;
+        u8 radar_detect_width = 0;
         int err;
 
         ASSERT_WDEV_LOCK(wdev);
@@ -114,14 +116,28 @@ int __cfg80211_join_ibss(struct cfg80211_registered_device *rdev,
         wdev->connect_keys = connkeys;
 
         wdev->ibss_fixed = params->channel_fixed;
+        wdev->ibss_dfs_possible = params->userspace_handles_dfs;
 #ifdef CONFIG_CFG80211_WEXT
         wdev->wext.ibss.chandef = params->chandef;
 #endif
+        check_chan = params->chandef.chan;
+        if (params->userspace_handles_dfs) {
+                /* use channel NULL to check for radar even if the current
+                 * channel is not a radar channel - it might decide to change
+                 * to DFS channel later.
+                 */
+                radar_detect_width = BIT(params->chandef.width);
+                check_chan = NULL;
+        }
+
+        err = cfg80211_can_use_iftype_chan(rdev, wdev, wdev->iftype,
+                                           check_chan,
+                                           (params->channel_fixed &&
+                                            !radar_detect_width)
+                                           ? CHAN_MODE_SHARED
+                                           : CHAN_MODE_EXCLUSIVE,
+                                           radar_detect_width);
 
-        err = cfg80211_can_use_chan(rdev, wdev, params->chandef.chan,
-                                    params->channel_fixed
-                                    ? CHAN_MODE_SHARED
-                                    : CHAN_MODE_EXCLUSIVE);
         if (err) {
                 wdev->connect_keys = NULL;
                 return err;