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>

1 files changed, 23 insertions, 1 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 7241962f9f13..1e3b4f730397 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -1197,6 +1197,24 @@ enum ieee80211_sta_state {
 };
 
 /**
+ * enum ieee80211_sta_rx_bandwidth - station RX bandwidth
+ * @IEEE80211_STA_RX_BW_20: station can only receive 20 MHz
+ * @IEEE80211_STA_RX_BW_40: station can receive up to 40 MHz
+ * @IEEE80211_STA_RX_BW_80: station can receive up to 80 MHz
+ * @IEEE80211_STA_RX_BW_160: station can receive up to 160 MHz
+ *	(including 80+80 MHz)
+ *
+ * Implementation note: 20 must be zero to be initialized
+ *	correctly, the values must be sorted.
+ */
+enum ieee80211_sta_rx_bandwidth {
+	IEEE80211_STA_RX_BW_20 = 0,
+	IEEE80211_STA_RX_BW_40,
+	IEEE80211_STA_RX_BW_80,
+	IEEE80211_STA_RX_BW_160,
+};
+
+/**
  * struct ieee80211_sta - station table entry
  *
  * A station table entry represents a station we are possibly
@@ -1218,6 +1236,7 @@ enum ieee80211_sta_state {
  * @uapsd_queues: bitmap of queues configured for uapsd. Only valid
  *	if wme is supported.
  * @max_sp: max Service Period. Only valid if wme is supported.
+ * @bandwidth: current bandwidth the station can receive with
  */
 struct ieee80211_sta {
 	u32 supp_rates[IEEE80211_NUM_BANDS];
@@ -1228,6 +1247,7 @@ struct ieee80211_sta {
 	bool wme;
 	u8 uapsd_queues;
 	u8 max_sp;
+	enum ieee80211_sta_rx_bandwidth bandwidth;
 
 	/* must be last */
 	u8 drv_priv[0] __aligned(sizeof(void *));
@@ -2086,7 +2106,9 @@ enum ieee80211_frame_release_type {
  * enum ieee80211_rate_control_changed - flags to indicate what changed
  *
  * @IEEE80211_RC_BW_CHANGED: The bandwidth that can be used to transmit
- *	to this station changed.
+ *	to this station changed. The actual bandwidth is in the station
+ *	information -- for HT20/40 the IEEE80211_HT_CAP_SUP_WIDTH_20_40
+ *	flag changes, for HT and VHT the bandwidth field changes.
  * @IEEE80211_RC_SMPS_CHANGED: The SMPS state of the station changed.
  * @IEEE80211_RC_SUPP_RATES_CHANGED: The supported rate set of this peer
  *	changed (in IBSS mode) due to discovering more information about