mac80211: improve HT channel handling

Currently, when one interface switches HT mode,
all others will follow along. This is clearly
undesirable, since the new one might switch to
no-HT while another one is operating in HT.

Address this issue by keeping track of the HT
mode per interface, and allowing only changes
that are compatible, i.e. switching into HT40+
is not possible when another interface is in
HT40-, in that case the second one needs to
fall back to HT20.

Also, to allow drivers to know what's going on,
store the per-interface HT mode (channel type)
in the virtual interface's bss_conf.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index d5855ae387e8..36745f494f63 100644
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -102,7 +102,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata,
         sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;
 
         local->oper_channel = chan;
-        local->oper_channel_type = NL80211_CHAN_NO_HT;
+        WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));
         ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
 
         sband = local->hw.wiphy->bands[chan->band];
@@ -910,7 +910,8 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,
         /* fix ourselves to that channel now already */
         if (params->channel_fixed) {
                 sdata->local->oper_channel = params->channel;
-                sdata->local->oper_channel_type = NL80211_CHAN_NO_HT;
+                WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,
+                                                    NL80211_CHAN_NO_HT));
         }
 
         if (params->ie) {