We were issuing probe requests to the associated AP on the wrong band by having our beacon timer loss trigger while we are scanning. When we would scan the timer could hit and force us to send a probe request to the AP but with a chance we'd be on the wrong band. This leads to finding no usable bitrate but we should not get so far on the xmit path. We should not be trying to send these probe request frames so prevent ieee80211_mgd_probe_ap() from sending these. As it turns out all callers of ieee80211_mgd_probe_ap() need this check so we just move the scan check there. This means we can remove the recenlty added check during ieee80211_sta_monitor_work(). Additionally we now fix a race condition added by the patch "mac80211: do not monitor the connection while scanning" which had the same check in ieee80211_sta_conn_mon_timer(). The race happens because the timer routine *does* a valid check for scanning but after it queues work into the mac80211 workqueue the work callback can kick off with scanning enabled and cause the same issue we were trying to avoid. The more appropriate solution would be to disable the respective timers during scan and re-enable them after scan but requires more complex code and testing. Cc: Christian Lamparter <chunkeey@xxxxxx> Cc: Larry Finger <Larry.Finger@xxxxxxxxxxxx> Reported-by: Fabio Rossi <rossi.f@xxxxxxxxx> Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx> --- net/mac80211/mlme.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 523c0d9..db0b4b2 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -1166,6 +1166,9 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata, if (!netif_running(sdata->dev)) return; + if (sdata->local->sw_scanning || sdata->local->hw_scanning) + return; + mutex_lock(&ifmgd->mtx); if (!ifmgd->associated) @@ -2213,9 +2216,6 @@ static void ieee80211_sta_monitor_work(struct work_struct *work) container_of(work, struct ieee80211_sub_if_data, u.mgd.monitor_work); - if (sdata->local->sw_scanning || sdata->local->hw_scanning) - return; - ieee80211_mgd_probe_ap(sdata, false); } -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
