qcacld-3.0: Complete all wait events before shutdown

There is a race condition between complete wait events as part of fw_down
indication and wait for timeout of stop_bss_event during stop_ap.

When stop ap and SSR runs parallel, first as part of SSR, fw_down
indication comes and all the wait_events are getting set. After this
as part of SAP stop, driver is waiting for stop_bss_event which will
be never set as fw_down indication is already processed. Timeout of
stop_bss_event is much higher than the timeout of wait-for-external-
thread-completion during shutdown, hence shutdown will proceed without
setting the stop_bss_event. Now as part of the SSR, hdd_re_init gets
invoked and the memory of the hdd_hostapd_state (and as part of this
memory of stop_bss_event) is getting memset inside hdd_init_ap_mode.
After this memset the timeout of the stop_bss_event occurs and
stop_bss_event tries to access this memset memory.

To address this issue, all the events which were added in between fw_down
indication and shutdown process, should be completed as part of
the shutdown.

Change-Id: I022f125b2afc99862351407b140f2d1b72f43bc4
CRs-Fixed: 2206326

core/hdd/src/wlan_hdd_driver_ops.c

@@ -555,6 +555,18 @@ static void wlan_hdd_shutdown(void)
 		hdd_err("Load/unload in progress, ignore SSR shutdown");
 		return;
 	}
+
+	/*
+	 * Force Complete all the wait events before shutdown.
+	 * This is done at "hdd_cleanup_on_fw_down" api also to clean up the
+	 * wait events of north bound apis.
+	 * In case of SSR there is significant dely between FW down event and
+	 * wlan_hdd_shutdown, there is a possibility of race condition that
+	 * these wait events gets complete at "hdd_cleanup_on_fw_down" and
+	 * some new event is added before shutdown.
+	 */
+	qdf_complete_wait_events();
+
 	/* this is for cases, where shutdown invoked from platform */
 	cds_set_recovery_in_progress(true);
 	hdd_wlan_ssr_shutdown_event();