ath10k: scan should handle scan-start-failed event properly

In case firmware fails to start the scan, then complete
the start condition and clean up so that driver does not
block on timeout.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/mac.c

@@ -2551,6 +2551,17 @@ static int ath10k_start_scan(struct ath10k *ar,
 		return -ETIMEDOUT;
 	}
 
+	/* If we failed to start the scan, return error code at
+	 * this point.  This is probably due to some issue in the
+	 * firmware, but no need to wedge the driver due to that...
+	 */
+	spin_lock_bh(&ar->data_lock);
+	if (ar->scan.state == ATH10K_SCAN_IDLE) {
+		spin_unlock_bh(&ar->data_lock);
+		return -EINVAL;
+	}
+	spin_unlock_bh(&ar->data_lock);
+
 	/* Add a 200ms margin to account for event/command processing */
 	ieee80211_queue_delayed_work(ar->hw, &ar->scan.timeout,
 				     msecs_to_jiffies(arg->max_scan_time+200));

drivers/net/wireless/ath/ath10k/wmi.c

@@ -1125,6 +1125,25 @@ static void ath10k_wmi_event_scan_started(struct ath10k *ar)
 	}
 }
 
+static void ath10k_wmi_event_scan_start_failed(struct ath10k *ar)
+{
+	lockdep_assert_held(&ar->data_lock);
+
+	switch (ar->scan.state) {
+	case ATH10K_SCAN_IDLE:
+	case ATH10K_SCAN_RUNNING:
+	case ATH10K_SCAN_ABORTING:
+		ath10k_warn(ar, "received scan start failed event in an invalid scan state: %s (%d)\n",
+			    ath10k_scan_state_str(ar->scan.state),
+			    ar->scan.state);
+		break;
+	case ATH10K_SCAN_STARTING:
+		complete(&ar->scan.started);
+		__ath10k_scan_finish(ar);
+		break;
+	}
+}
+
 static void ath10k_wmi_event_scan_completed(struct ath10k *ar)
 {
 	lockdep_assert_held(&ar->data_lock);
@@ -1292,6 +1311,7 @@ int ath10k_wmi_event_scan(struct ath10k *ar, struct sk_buff *skb)
 		break;
 	case WMI_SCAN_EVENT_START_FAILED:
 		ath10k_warn(ar, "received scan start failure event\n");
+		ath10k_wmi_event_scan_start_failed(ar);
 		break;
 	case WMI_SCAN_EVENT_DEQUEUED:
 	case WMI_SCAN_EVENT_PREEMPTED: