mac80211: stop toggling IEEE80211_HT_CAP_SUP_WIDTH_20_40

For VHT, many more bandwidth changes are possible. As a first
step, stop toggling the IEEE80211_HT_CAP_SUP_WIDTH_20_40 flag
in the HT capabilities and instead introduce a bandwidth field
indicating the currently usable bandwidth to transmit to the
station. Of course, make all drivers use it.

To achieve this, make ieee80211_ht_cap_ie_to_sta_ht_cap() get
the station as an argument, rather than the new capabilities,
so it can set up the new bandwidth field.

If the station is a VHT station and VHT bandwidth is in use,
also set the bandwidth accordingly.

Doing this allows us to get rid of the supports_40mhz flag as
the HT capabilities now reflect the true capability instead of
the current setting.

While at it, also fix ieee80211_ht_cap_ie_to_sta_ht_cap() to not
ignore HT cap overrides when MCS TX isn't supported (not that it
really happens...)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c b/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c
index d1f34f6..1b65db7 100644
--- a/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c
+++ b/drivers/net/wireless/rtlwifi/rtl8192ce/hw.c
@@ -1846,9 +1846,9 @@
 	struct rtl_sta_info *sta_entry = NULL;
 	u32 ratr_bitmap;
 	u8 ratr_index;
-	u8 curtxbw_40mhz = (sta->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40)
-				? 1 : 0;
-	u8 curshortgi_40mhz = (sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_40) ?
+	u8 curtxbw_40mhz = (sta->bandwidth >= IEEE80211_STA_RX_BW_40) ? 1 : 0;
+	u8 curshortgi_40mhz = curtxbw_40mhz &&
+			      (sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_40) ?
 				1 : 0;
 	u8 curshortgi_20mhz = (sta->ht_cap.cap & IEEE80211_HT_CAP_SGI_20) ?
 				1 : 0;