qcacld-3.0: Flush scan results on interface down

After successful connection, if interface down(STA) happens on DUT
and if AP changes data rates before interface up happens, there
is a possibility of STA to send packets at older data rates, because
of holding older scan results in SME scan cache. This results in using
stale scan result even after wifi turn off and on. If stale scan result
is used and if AP has updated some params like rates DUT will not be
using those supported rates for tx which is an issue.

To mitigate this issue, flush scan results on STA interface down.
Also, make sure there are no other STA interfaces before flushing
scan results.

Change-Id: I3505c128276fa8e5e05ea5d9110eb75275a746e9
CRs-Fixed: 2171523

core/hdd/inc/wlan_hdd_main.h

@@ -1,4 +1,4 @@
-/*
+ /*
  * Copyright (c) 2012-2018 The Linux Foundation. All rights reserved.
  *
  * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
@@ -2871,4 +2871,13 @@ void hdd_driver_memdump_deinit(void);
 uint8_t hdd_check_green_ap_enable(struct hdd_context *hdd_ctx,
 				     bool *is_enabled);
 
+/**
+ * hdd_is_cli_iface_up() - check if there is any cli iface up
+ * @hdd_ctx: HDD context
+ *
+ * Return: return true if there is any cli iface(STA/P2P_CLI) is up
+ *         else return false
+ */
+bool hdd_is_cli_iface_up(struct hdd_context *hdd_ctx);
+
 #endif /* end #if !defined(WLAN_HDD_MAIN_H) */

core/hdd/src/wlan_hdd_hostapd.c

@@ -518,6 +518,10 @@ static int __hdd_hostapd_stop(struct net_device *dev)
 	hdd_stop_adapter(hdd_ctx, adapter);
 	hdd_deinit_adapter(hdd_ctx, adapter, true);
 	clear_bit(DEVICE_IFACE_OPENED, &adapter->event_flags);
+
+	if (!hdd_is_cli_iface_up(hdd_ctx))
+		sme_scan_flush_result(hdd_ctx->hHal);
+
 	/* Stop all tx queues */
 	hdd_debug("Disabling queues");
 	wlan_hdd_netif_queue_control(adapter,

core/hdd/src/wlan_hdd_main.c

@@ -3006,6 +3006,13 @@ static int __hdd_stop(struct net_device *dev)
 	hdd_deinit_adapter(hdd_ctx, adapter, true);
 
 
+	/*
+	 * Upon wifi turn off, DUT has to flush the scan results so if
+	 * this is the last cli iface, flush the scan database.
+	 */
+	if (!hdd_is_cli_iface_up(hdd_ctx))
+		sme_scan_flush_result(hdd_ctx->hHal);
+
 	/*
 	 * Find if any iface is up. If any iface is up then can't put device to
 	 * sleep/power save mode
@@ -13599,6 +13606,22 @@ void hdd_set_rx_mode_rps(bool enable)
 	}
 }
 
+bool hdd_is_cli_iface_up(struct hdd_context *hdd_ctx)
+{
+	struct hdd_adapter *adapter = NULL;
+
+	hdd_for_each_adapter(hdd_ctx, adapter) {
+		if ((adapter->device_mode == QDF_STA_MODE ||
+		     adapter->device_mode == QDF_P2P_CLIENT_MODE) &&
+		    qdf_atomic_test_bit(DEVICE_IFACE_OPENED,
+					&adapter->event_flags)){
+			return true;
+		}
+	}
+
+	return false;
+}
+
 /* Register the module init/exit functions */
 module_init(hdd_module_init);
 module_exit(hdd_module_exit);