mac80211: allow driver to return error from sched_scan_stop

In order to solve races with sched_scan_stop, it is necessary
for the driver to be able to return an error to propagate that
to cfg80211 so it doesn't send an event.

Reviewed-by: Alexander Bondar <alexander.bondar@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

2 files changed, 9 insertions, 5 deletions

diff --git a/net/mac80211/driver-ops.h b/net/mac80211/driver-ops.h
index ef8b385eff04..fc689f5d971e 100644
--- a/net/mac80211/driver-ops.h
+++ b/net/mac80211/driver-ops.h
@@ -354,16 +354,20 @@ drv_sched_scan_start(struct ieee80211_local *local,
         return ret;
 }
 
-static inline void drv_sched_scan_stop(struct ieee80211_local *local,
-                                       struct ieee80211_sub_if_data *sdata)
+static inline int drv_sched_scan_stop(struct ieee80211_local *local,
+                                      struct ieee80211_sub_if_data *sdata)
 {
+        int ret;
+
         might_sleep();
 
         check_sdata_in_driver(sdata);
 
         trace_drv_sched_scan_stop(local, sdata);
-        local->ops->sched_scan_stop(&local->hw, &sdata->vif);
-        trace_drv_return_void(local);
+        ret = local->ops->sched_scan_stop(&local->hw, &sdata->vif);
+        trace_drv_return_int(local, ret);
+
+        return ret;
 }
 
 static inline void drv_sw_scan_start(struct ieee80211_local *local)
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index b211e412511f..836f500dfbf3 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -1056,7 +1056,7 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
         local->sched_scan_req = NULL;
 
         if (rcu_access_pointer(local->sched_scan_sdata))
-                drv_sched_scan_stop(local, sdata);
+                ret = drv_sched_scan_stop(local, sdata);
 
 out:
         mutex_unlock(&local->mtx);