mac80211: fix ibss scan parameters

commit d321cd014e51baab475efbdec468255b9e0ec822 upstream.

When joining IBSS a full scan should be initiated in order to search
for existing cell, unless the fixed_channel parameter was set.
A default channel to create the IBSS on if no cell was found is
provided as well.
However - a scan is initiated only on the default channel provided
regardless of whether ifibss->fixed_channel is set or not, with the
obvious result of the cell not joining existing IBSS cell that is
on another channel.

Fixes: 76bed0f43b27 ("mac80211: IBSS fix scan request")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 6a12b0f5cac871e7906b7fee7a5da868b21d25c7..980e9e9b6684fd28fc65014550e83871ca37a282 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -7,6 +7,7 @@
  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
  * Copyright 2009, Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
+ * Copyright(c) 2016 Intel Deutschland GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -1484,14 +1485,21 @@ static void ieee80211_sta_find_ibss(struct ieee80211_sub_if_data *sdata)
 
                sdata_info(sdata, "Trigger new scan to find an IBSS to join\n");
 
-               num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
-                                                        &ifibss->chandef,
-                                                        channels,
-                                                        ARRAY_SIZE(channels));
                scan_width = cfg80211_chandef_to_scan_width(&ifibss->chandef);
-               ieee80211_request_ibss_scan(sdata, ifibss->ssid,
-                                           ifibss->ssid_len, channels, num,
-                                           scan_width);
+
+               if (ifibss->fixed_channel) {
+                       num = ieee80211_ibss_setup_scan_channels(local->hw.wiphy,
+                                                                &ifibss->chandef,
+                                                                channels,
+                                                                ARRAY_SIZE(channels));
+                       ieee80211_request_ibss_scan(sdata, ifibss->ssid,
+                                                   ifibss->ssid_len, channels,
+                                                   num, scan_width);
+               } else {
+                       ieee80211_request_ibss_scan(sdata, ifibss->ssid,
+                                                   ifibss->ssid_len, NULL,
+                                                   0, scan_width);
+               }
        } else {
                int interval = IEEE80211_SCAN_INTERVAL;