[ Upstream commit 5dc8cdce1d722c733f8c7af14c5fb595cfedbfa8 ]
FullMAC STAs have no way to update bss channel after CSA channel switch completion. As a result, user-space tools may provide inconsistent channel info. For instance, consider the following two commands: $ sudo iw dev wlan0 link $ sudo iw dev wlan0 info The latter command gets channel info from the hardware, so most probably its output will be correct. However the former command gets channel info from scan cache, so its output will contain outdated channel info. In fact, current bss channel info will not be updated until the next [re-]connect.
Note that mac80211 STAs have a workaround for this, but it requires access to internal cfg80211 data, see ieee80211_chswitch_work:
/* XXX: shouldn't really modify cfg80211-owned data! */ ifmgd->associated->channel = sdata->csa_chandef.chan;
This patch suggests to convert mac80211 workaround into cfg80211 behavior and to update current bss channel in cfg80211_ch_switch_notify.
Signed-off-by: Sergey Matyukevich sergey.matyukevich.os@quantenna.com Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/mac80211/mlme.c | 3 --- net/wireless/nl80211.c | 5 +++++ 2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 6878215672871..715ab0e6579cb 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -1167,9 +1167,6 @@ static void ieee80211_chswitch_work(struct work_struct *work) goto out; }
- /* XXX: shouldn't really modify cfg80211-owned data! */ - ifmgd->associated->channel = sdata->csa_chandef.chan; - ifmgd->csa_waiting_bcn = true;
ieee80211_sta_reset_beacon_monitor(sdata); diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 156ce708b5330..0044bfb526abc 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -15667,6 +15667,11 @@ void cfg80211_ch_switch_notify(struct net_device *dev,
wdev->chandef = *chandef; wdev->preset_chandef = *chandef; + + if (wdev->iftype == NL80211_IFTYPE_STATION && + !WARN_ON(!wdev->current_bss)) + wdev->current_bss->pub.channel = chandef->chan; + nl80211_ch_switch_notify(rdev, dev, chandef, GFP_KERNEL, NL80211_CMD_CH_SWITCH_NOTIFY, 0); }