From 15db0b7fd872b0312033666d3a82e1214a227ec0 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 25 Aug 2009 16:33:47 +0200 Subject: [PATCH] mac80211: fix scan cancel on ifdown When an interface is taken down while a scan is pending -- i.e. a scan request was accepted but not yet acted upon due to other work being in progress -- we currently do not properly cancel that scan and end up getting stuck. Fix this by doing better checks when an interface is taken down. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/iface.c | 26 ++------------------------ net/mac80211/scan.c | 9 ++++++--- 2 files changed, 8 insertions(+), 27 deletions(-) diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c index d134bd79972f..f6005adcbf90 100644 --- a/net/mac80211/iface.c +++ b/net/mac80211/iface.c @@ -497,30 +497,8 @@ static int ieee80211_stop(struct net_device *dev) } /* fall through */ default: - if (local->scan_sdata == sdata) { - if (!local->ops->hw_scan) - cancel_delayed_work_sync(&local->scan_work); - /* - * The software scan can no longer run now, so we can - * clear out the scan_sdata reference. However, the - * hardware scan may still be running. The complete - * function must be prepared to handle a NULL value. - */ - local->scan_sdata = NULL; - /* - * The memory barrier guarantees that another CPU - * that is hardware-scanning will now see the fact - * that this interface is gone. - */ - smp_mb(); - /* - * If software scanning, complete the scan but since - * the scan_sdata is NULL already don't send out a - * scan event to userspace -- the scan is incomplete. - */ - if (test_bit(SCAN_SW_SCANNING, &local->scanning)) - ieee80211_scan_completed(&local->hw, true); - } + if (local->scan_sdata == sdata) + ieee80211_scan_cancel(local); /* * Disable beaconing for AP and mesh, IBSS can't diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 1e04be6b9129..039901109fa1 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -280,6 +280,7 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) if (local->scan_req != local->int_scan_req) cfg80211_scan_done(local->scan_req, aborted); local->scan_req = NULL; + local->scan_sdata = NULL; was_hw_scan = test_bit(SCAN_HW_SCANNING, &local->scanning); local->scanning = 0; @@ -660,6 +661,7 @@ void ieee80211_scan_work(struct work_struct *work) int rc; local->scan_req = NULL; + local->scan_sdata = NULL; rc = __ieee80211_start_scan(sdata, req); mutex_unlock(&local->scan_mtx); @@ -742,7 +744,7 @@ int ieee80211_request_internal_scan(struct ieee80211_sub_if_data *sdata, void ieee80211_scan_cancel(struct ieee80211_local *local) { - bool swscan; + bool abortscan; cancel_delayed_work_sync(&local->scan_work); @@ -751,9 +753,10 @@ void ieee80211_scan_cancel(struct ieee80211_local *local) * queued -- mostly at suspend under RTNL. */ mutex_lock(&local->scan_mtx); - swscan = test_bit(SCAN_SW_SCANNING, &local->scanning); + abortscan = test_bit(SCAN_SW_SCANNING, &local->scanning) || + (!local->scanning && local->scan_req); mutex_unlock(&local->scan_mtx); - if (swscan) + if (abortscan) ieee80211_scan_completed(&local->hw, true); } -- GitLab