mac80211: fix ibss scan parameters

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>

1 files changed, 15 insertions, 7 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index e5e8a317b865..9b983788ee51 100644
--- 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
@@ -1483,14 +1484,21 @@ 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;