mac80211: reschedule sched scan after HW restart

Keep the sched scan req when starting sched scan, and reschedule
it in case of HW restart during sched scan.
The upper layer don't have to know about the restart.

Signed-off-by: David Spinadel <david.spinadel@intel.com>
Reviewed-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 39 insertions, 14 deletions

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index ee6c851..88c8161 100644
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -971,8 +971,8 @@ out:
 	mutex_unlock(&local->mtx);
 }
 
-int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
-				       struct cfg80211_sched_scan_request *req)
+int __ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
+					struct cfg80211_sched_scan_request *req)
 {
 	struct ieee80211_local *local = sdata->local;
 	struct ieee80211_sched_scan_ies sched_scan_ies = {};
@@ -982,17 +982,10 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 	iebufsz = 2 + IEEE80211_MAX_SSID_LEN +
 		  local->scan_ies_len + req->ie_len;
 
-	mutex_lock(&local->mtx);
+	lockdep_assert_held(&local->mtx);
 
-	if (rcu_access_pointer(local->sched_scan_sdata)) {
-		ret = -EBUSY;
-		goto out;
-	}
-
-	if (!local->ops->sched_scan_start) {
-		ret = -ENOTSUPP;
-		goto out;
-	}
+	if (!local->ops->sched_scan_start)
+		return -ENOTSUPP;
 
 	for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
 		if (!local->hw.wiphy->bands[i])
@@ -1013,13 +1006,39 @@ int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
 	}
 
 	ret = drv_sched_scan_start(local, sdata, req, &sched_scan_ies);
-	if (ret == 0)
+	if (ret == 0) {
 		rcu_assign_pointer(local->sched_scan_sdata, sdata);
+		local->sched_scan_req = req;
+	}
 
 out_free:
 	while (i > 0)
 		kfree(sched_scan_ies.ie[--i]);
-out:
+
+	if (ret) {
+		/* Clean in case of failure after HW restart or upon resume. */
+		rcu_assign_pointer(local->sched_scan_sdata, NULL);
+		local->sched_scan_req = NULL;
+	}
+
+	return ret;
+}
+
+int ieee80211_request_sched_scan_start(struct ieee80211_sub_if_data *sdata,
+				       struct cfg80211_sched_scan_request *req)
+{
+	struct ieee80211_local *local = sdata->local;
+	int ret;
+
+	mutex_lock(&local->mtx);
+
+	if (rcu_access_pointer(local->sched_scan_sdata)) {
+		mutex_unlock(&local->mtx);
+		return -EBUSY;
+	}
+
+	ret = __ieee80211_request_sched_scan_start(sdata, req);
+
 	mutex_unlock(&local->mtx);
 	return ret;
 }
@@ -1036,6 +1055,9 @@ int ieee80211_request_sched_scan_stop(struct ieee80211_sub_if_data *sdata)
 		goto out;
 	}
 
+	/* We don't want to restart sched scan anymore. */
+	local->sched_scan_req = NULL;
+
 	if (rcu_access_pointer(local->sched_scan_sdata))
 		drv_sched_scan_stop(local, sdata);
 
@@ -1070,6 +1092,9 @@ void ieee80211_sched_scan_stopped_work(struct work_struct *work)
 
 	rcu_assign_pointer(local->sched_scan_sdata, NULL);
 
+	/* If sched scan was aborted by the driver. */
+	local->sched_scan_req = NULL;
+
 	mutex_unlock(&local->mtx);
 
 	cfg80211_sched_scan_stopped(local->hw.wiphy);