diff options
| author | Emmanuel Grumbach <emmanuel.grumbach@intel.com> | 2013-09-16 12:12:07 +0400 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2013-10-09 20:40:07 +0400 |
| commit | a754055a1296fcbe6f32de3a5eaca6efb2fd1865 (patch) | |
| tree | 6812b556c369c031478a94d6de4b2b6259bd2ca9 /net/mac80211/scan.c | |
| parent | 22c4ceed0184318ec5a6182c6d75d398452c2e39 (diff) | |
| download | linux-a754055a1296fcbe6f32de3a5eaca6efb2fd1865.tar.xz | |
mac80211: correctly close cancelled scans
__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.
Cc: stable@vger.kernel.org
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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 08afe74b98f4..d2d17a449224 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -238,6 +238,9 @@ 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; @@ -940,7 +943,23 @@ 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, |