diff options
| author | Emmanuel Grumbach <emmanuel.grumbach@intel.com> | 2013-09-16 11:12:07 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-13 12:05:30 +0900 |
| commit | 715a606d73f63e94259e6251565e6e12e3271d0f (patch) | |
| tree | 2d8dd2d9ff41caf6aa7820b60605bc3aa592baec /net/mac80211/scan.c | |
| parent | 5be794dc4bb66266acc91eb589ace48e82a6c77e (diff) | |
mac80211: correctly close cancelled scans
commit a754055a1296fcbe6f32de3a5eaca6efb2fd1865 upstream.
__ieee80211_scan_completed is called from a worker. This
means that the following flow is possible.
* driver calls ieee80211_scan_completed
* mac80211 cancels the scan (that is already complete)
* __ieee80211_scan_completed runs
When scan_work will finally run, it will see that the scan
hasn't been aborted and might even trigger another scan on
another band. This leads to a situation where cfg80211's
scan is not done and no further scan can be issued.
Fix this by setting a new flag when a HW scan is being
cancelled so that no other scan will be triggered.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/mac80211/scan.c')
| -rw-r--r-- | net/mac80211/scan.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index 99b103921a4b..eb03337b6545 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -202,6 +202,9 @@ static bool ieee80211_prep_hw_scan(struct ieee80211_local *local) enum ieee80211_band band; int i, ielen, n_chans; + if (test_bit(SCAN_HW_CANCELLED, &local->scanning)) + return false; + do { if (local->hw_scan_band == IEEE80211_NUM_BANDS) return false; @@ -878,7 +881,23 @@ void ieee80211_scan_cancel(struct ieee80211_local *local) if (!local->scan_req) goto out; + /* + * We have a scan running and the driver already reported completion, + * but the worker hasn't run yet or is stuck on the mutex - mark it as + * cancelled. + */ + if (test_bit(SCAN_HW_SCANNING, &local->scanning) && + test_bit(SCAN_COMPLETED, &local->scanning)) { + set_bit(SCAN_HW_CANCELLED, &local->scanning); + goto out; + } + if (test_bit(SCAN_HW_SCANNING, &local->scanning)) { + /* + * Make sure that __ieee80211_scan_completed doesn't trigger a + * scan on another band. + */ + set_bit(SCAN_HW_CANCELLED, &local->scanning); if (local->ops->cancel_hw_scan) drv_cancel_hw_scan(local, rcu_dereference_protected(local->scan_sdata, |