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, 0 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 0528615ac827..9448a5b1bb15 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -191,6 +191,9 @@ enum ieee80211_bss_change {
  *      the current band.
  * @bssid: The BSSID for this BSS
  * @enable_beacon: whether beaconing should be enabled or not
+ * @channel_type: Channel type for this BSS -- the hardware might be
+ *      configured for HT40+ while this BSS only uses no-HT, for
+ *      example.
  * @ht_operation_mode: HT operation mode (like in &struct ieee80211_ht_info).
  *      This field is only valid when the channel type is one of the HT types.
  * @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value
@@ -215,6 +218,7 @@ struct ieee80211_bss_conf {
         u16 ht_operation_mode;
         s32 cqm_rssi_thold;
         u32 cqm_rssi_hyst;
+        enum nl80211_channel_type channel_type;
 };
 
 /**