mac80211: refactor set_channel_type

Split functionality for further reuse.

Will prevent code duplication when channel context
channel_type merging is introduced.

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

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index f0f87e5a1d354eef6a705deba7a15c21b491093f..0bfc914ddd1504d16a2ebf8ad74655d6deb60e53 100644 (file)
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -68,16 +68,14 @@ ieee80211_get_channel_mode(struct ieee80211_local *local,
        return mode;
 }
 
-bool ieee80211_set_channel_type(struct ieee80211_local *local,
-                               struct ieee80211_sub_if_data *sdata,
-                               enum nl80211_channel_type chantype)
+static enum nl80211_channel_type
+ieee80211_get_superchan(struct ieee80211_local *local,
+                       struct ieee80211_sub_if_data *sdata)
 {
-       struct ieee80211_sub_if_data *tmp;
        enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;
-       bool result;
+       struct ieee80211_sub_if_data *tmp;
 
        mutex_lock(&local->iflist_mtx);
-
        list_for_each_entry(tmp, &local->interfaces, list) {
                if (tmp == sdata)
                        continue;
@@ -103,39 +101,70 @@ bool ieee80211_set_channel_type(struct ieee80211_local *local,
                        break;
                }
        }
+       mutex_unlock(&local->iflist_mtx);
 
-       switch (superchan) {
+       return superchan;
+}
+
+static bool
+ieee80211_channel_types_are_compatible(enum nl80211_channel_type chantype1,
+                                      enum nl80211_channel_type chantype2,
+                                      enum nl80211_channel_type *compat)
+{
+       /*
+        * start out with chantype1 being the result,
+        * overwriting later if needed
+        */
+       if (compat)
+               *compat = chantype1;
+
+       switch (chantype1) {
        case NL80211_CHAN_NO_HT:
+               if (compat)
+                       *compat = chantype2;
+               break;
        case NL80211_CHAN_HT20:
                /*
                 * allow any change that doesn't go to no-HT
                 * (if it already is no-HT no change is needed)
                 */
-               if (chantype == NL80211_CHAN_NO_HT)
+               if (chantype2 == NL80211_CHAN_NO_HT)
                        break;
-               superchan = chantype;
+               if (compat)
+                       *compat = chantype2;
                break;
        case NL80211_CHAN_HT40PLUS:
        case NL80211_CHAN_HT40MINUS:
                /* allow smaller bandwidth and same */
-               if (chantype == NL80211_CHAN_NO_HT)
+               if (chantype2 == NL80211_CHAN_NO_HT)
                        break;
-               if (chantype == NL80211_CHAN_HT20)
+               if (chantype2 == NL80211_CHAN_HT20)
                        break;
-               if (superchan == chantype)
+               if (chantype2 == chantype1)
                        break;
-               result = false;
-               goto out;
+               return false;
        }
 
-       local->_oper_channel_type = superchan;
+       return true;
+}
+
+bool ieee80211_set_channel_type(struct ieee80211_local *local,
+                               struct ieee80211_sub_if_data *sdata,
+                               enum nl80211_channel_type chantype)
+{
+       enum nl80211_channel_type superchan;
+       enum nl80211_channel_type compatchan;
+
+       superchan = ieee80211_get_superchan(local, sdata);
+       if (!ieee80211_channel_types_are_compatible(superchan, chantype,
+                                                   &compatchan))
+               return false;
+
+       local->_oper_channel_type = compatchan;
 
        if (sdata)
                sdata->vif.bss_conf.channel_type = chantype;
 
-       result = true;
- out:
-       mutex_unlock(&local->iflist_mtx);
+       return true;
 
-       return result;
 }