[PATCH 4.9 20/59] mac80211: Fix station bandwidth setting after channel switch

Greg Kroah-Hartman
2018-10-08T18:39:59Z

From: Ilan Peer <ilan.peer@intel.com>

[ Upstream commit 0007e94355fdb71a1cf5dba0754155cba08f0666 ]

When performing a channel switch flow for a managed interface, the
flow did not update the bandwidth of the AP station and the rate
scale algorithm. In case of a channel width downgrade, this would
result with the rate scale algorithm using a bandwidth that does not
match the interface channel configuration.

Fix this by updating the AP station bandwidth and rate scaling algorithm
before the actual channel change in case of a bandwidth downgrade, or
after the actual channel change in case of a bandwidth upgrade.

Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/mac80211/mlme.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)

--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -989,6 +989,10 @@ static void ieee80211_chswitch_work(stru
*/

if (sdata->reserved_chanctx) {
+ struct ieee80211_supported_band *sband = NULL;
+ struct sta_info *mgd_sta = NULL;
+ enum ieee80211_sta_rx_bandwidth bw = IEEE80211_STA_RX_BW_20;
+
/*
* with multi-vif csa driver may call ieee80211_csa_finish()
* many times while waiting for other interfaces to use their
@@ -997,6 +1001,48 @@ static void ieee80211_chswitch_work(stru
if (sdata->reserved_ready)
goto out;

+ if (sdata->vif.bss_conf.chandef.width !=
+ sdata->csa_chandef.width) {
+ /*
+ * For managed interface, we need to also update the AP
+ * station bandwidth and align the rate scale algorithm
+ * on the bandwidth change. Here we only consider the
+ * bandwidth of the new channel definition (as channel
+ * switch flow does not have the full HT/VHT/HE
+ * information), assuming that if additional changes are
+ * required they would be done as part of the processing
+ * of the next beacon from the AP.
+ */
+ switch (sdata->csa_chandef.width) {
+ case NL80211_CHAN_WIDTH_20_NOHT:
+ case NL80211_CHAN_WIDTH_20:
+ default:
+ bw = IEEE80211_STA_RX_BW_20;
+ break;
+ case NL80211_CHAN_WIDTH_40:
+ bw = IEEE80211_STA_RX_BW_40;
+ break;
+ case NL80211_CHAN_WIDTH_80:
+ bw = IEEE80211_STA_RX_BW_80;
+ break;
+ case NL80211_CHAN_WIDTH_80P80:
+ case NL80211_CHAN_WIDTH_160:
+ bw = IEEE80211_STA_RX_BW_160;
+ break;
+ }
+
+ mgd_sta = sta_info_get(sdata, ifmgd->bssid);
+ sband =
+ local->hw.wiphy->bands[sdata->csa_chandef.chan->band];
+ }
+
+ if (sdata->vif.bss_conf.chandef.width >
+ sdata->csa_chandef.width) {
+ mgd_sta->sta.bandwidth = bw;
+ rate_control_rate_update(local, sband, mgd_sta,
+ IEEE80211_RC_BW_CHANGED);
+ }
+
ret = ieee80211_vif_use_reserved_context(sdata);
if (ret) {
sdata_info(sdata,
@@ -1007,6 +1053,13 @@ static void ieee80211_chswitch_work(stru
goto out;
}

+ if (sdata->vif.bss_conf.chandef.width <
+ sdata->csa_chandef.width) {
+ mgd_sta->sta.bandwidth = bw;
+ rate_control_rate_update(local, sband, mgd_sta,
+ IEEE80211_RC_BW_CHANGED);
+ }
+
goto out;
}