mac80211: Support ht-cap over-rides.

This implements ht-cap over-rides for mac80211 drivers.
HT may be disabled, making an /a/b/g/n station act like an
a/b/g station.  HT40 may be disabled forcing the station to
be HT20 even if the AP and local hardware support HT40.

MAX-AMSDU may be disabled.
AMPDU-Density may be increased.
AMPDU-Factor may be decreased.

This has been successfully tested with ath9k using patched
wpa_supplicant and iw.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index e2cb00df8c36..1118393d79de 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -979,7 +979,8 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer,
         }
 
         if (sband->ht_cap.ht_supported)
-                pos = ieee80211_ie_build_ht_cap(pos, sband, sband->ht_cap.cap);
+                pos = ieee80211_ie_build_ht_cap(pos, &sband->ht_cap,
+                                                sband->ht_cap.cap);
 
         /*
          * If adding more here, adjust code in main.c
@@ -1518,7 +1519,7 @@ void ieee80211_disable_rssi_reports(struct ieee80211_vif *vif)
 }
 EXPORT_SYMBOL(ieee80211_disable_rssi_reports);
 
-u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_supported_band *sband,
+u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_sta_ht_cap *ht_cap,
                               u16 cap)
 {
         __le16 tmp;
@@ -1533,13 +1534,13 @@ u8 *ieee80211_ie_build_ht_cap(u8 *pos, struct ieee80211_supported_band *sband,
         pos += sizeof(u16);
 
         /* AMPDU parameters */
-        *pos++ = sband->ht_cap.ampdu_factor |
-                 (sband->ht_cap.ampdu_density <<
+        *pos++ = ht_cap->ampdu_factor |
+                 (ht_cap->ampdu_density <<
                         IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT);
 
         /* MCS set */
-        memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs));
-        pos += sizeof(sband->ht_cap.mcs);
+        memcpy(pos, &ht_cap->mcs, sizeof(ht_cap->mcs));
+        pos += sizeof(ht_cap->mcs);
 
         /* extended capabilities */
         pos += sizeof(__le16);