From b33fb28c867d7c86df3bdd257b0320ed148e3dc3 Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Thu, 21 Oct 2021 10:45:27 +0200 Subject: [PATCH] mac80211: Prevent AP probing during suspend Submitting AP probe/null during suspend can cause unexpected disconnect on resume because of timeout waiting for ack status: wlan0: Failed to send nullfunc to AP 11:22:33:44:55:66 after 500ms, disconnecting This is especially the case when we enter suspend when a scan is ongoing, indeed, scan is cancelled from __ieee80211_suspend, leading to a corresponding (aborted) scan complete event, which in turn causes the submission of an immediate monitor null frame (restart_sta_timer). The corresponding packet or ack will not be processed before resuming, causing a timeout & disconnect on resume. Delay the AP probing when suspending/suspended. Signed-off-by: Loic Poulain Link: https://lore.kernel.org/r/1634805927-1113-1-git-send-email-loic.poulain@linaro.org Signed-off-by: Johannes Berg --- net/mac80211/ieee80211_i.h | 3 +++ net/mac80211/mlme.c | 7 +++++++ net/mac80211/pm.c | 4 ++++ 3 files changed, 14 insertions(+) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index c3b8590a7e90..5666bbb8860b 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1241,6 +1241,9 @@ struct ieee80211_local { */ bool suspended; + /* suspending is true during the whole suspend process */ + bool suspending; + /* * Resuming is true while suspended, but when we're reprogramming the * hardware -- at that time it's allowed to use ieee80211_queue_work() diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 16ef7396b6da..54ab0e1ef6ca 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2589,6 +2589,13 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata, goto out; } + if (sdata->local->suspending) { + /* reschedule after resume */ + mutex_unlock(&sdata->local->mtx); + ieee80211_reset_ap_probe(sdata); + goto out; + } + if (beacon) { mlme_dbg_ratelimited(sdata, "detected beacon loss from AP (missed %d beacons) - probing\n", diff --git a/net/mac80211/pm.c b/net/mac80211/pm.c index 7809a906d7fe..0ccb5701c7f3 100644 --- a/net/mac80211/pm.c +++ b/net/mac80211/pm.c @@ -27,6 +27,9 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan) if (!local->open_count) goto suspend; + local->suspending = true; + mb(); /* make suspending visible before any cancellation */ + ieee80211_scan_cancel(local); ieee80211_dfs_cac_cancel(local); @@ -176,6 +179,7 @@ int __ieee80211_suspend(struct ieee80211_hw *hw, struct cfg80211_wowlan *wowlan) /* need suspended to be visible before quiescing is false */ barrier(); local->quiescing = false; + local->suspending = false; return 0; }