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, 4 insertions, 1 deletions

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 359edff31471..69e7f4131f46 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -768,7 +768,7 @@ struct ieee80211_local {
         enum mac80211_scan_state next_scan_state;
         struct delayed_work scan_work;
         struct ieee80211_sub_if_data *scan_sdata;
-        enum nl80211_channel_type oper_channel_type;
+        enum nl80211_channel_type _oper_channel_type;
         struct ieee80211_channel *oper_channel, *csa_channel;
 
         /* Temporary remain-on-channel for off-channel operations */
@@ -1239,6 +1239,9 @@ enum ieee80211_chan_mode {
 enum ieee80211_chan_mode
 ieee80211_get_channel_mode(struct ieee80211_local *local,
                            struct ieee80211_sub_if_data *ignore);
+bool ieee80211_set_channel_type(struct ieee80211_local *local,
+                                struct ieee80211_sub_if_data *sdata,
+                                enum nl80211_channel_type chantype);
 
 #ifdef CONFIG_MAC80211_NOINLINE
 #define debug_noinline noinline