qcacld-3.0: Add CDS SSR ready check for driver unload

Driver unload is not waiting for external threads to exit
before starting clean up process. Add CDS SSR ready check
for driver unload such that driver unload waits for all
external threads to exit before cleaning up driver data
structures.

Change-Id: Ic5ac1b770dea8e470ed8dcce50a4f66451f918f1
CRs-Fixed: 964151

core/cds/inc/cds_sched.h

@@ -438,9 +438,7 @@ void cdf_timer_module_init(void);
 void cds_ssr_protect_init(void);
 void cds_ssr_protect(const char *caller_func);
 void cds_ssr_unprotect(const char *caller_func);
-bool cds_is_ssr_ready(const char *caller_func);
+bool cds_wait_for_external_threads_completion(const char *caller_func);
 int cds_get_gfp_flags(void);
 
-#define cds_wait_for_work_thread_completion(func) cds_is_ssr_ready(func)
-
 #endif /* #if !defined __CDS_SCHED_H */

core/cds/src/cds_sched.c

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2015 The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014-2016 The Linux Foundation. All rights reserved.
  *
  * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
  *
@@ -1230,14 +1230,14 @@ void cds_ssr_unprotect(const char *caller_func)
 }
 
 /**
- * cds_is_ssr_ready() - check if the calling execution can proceed with ssr
- *
+ * cds_wait_for_external_threads_completion() - wait for external threads
+ *					completion before proceeding further
  * @caller_func: name of calling function.
  *
  * Return: true if there is no active entry points in driver
  *	   false if there is at least one active entry in driver
  */
-bool cds_is_ssr_ready(const char *caller_func)
+bool cds_wait_for_external_threads_completion(const char *caller_func)
 {
 	int count = MAX_SSR_WAIT_ITERATIONS;
 
@@ -1260,7 +1260,7 @@ bool cds_is_ssr_ready(const char *caller_func)
 	}
 
 	CDF_TRACE(CDF_MODULE_ID_CDF, CDF_TRACE_LEVEL_INFO,
-		  "Allowing SSR for %s", caller_func);
+		  "Allowing SSR/Driver unload for %s", caller_func);
 
 	return true;
 }

core/hdd/src/wlan_hdd_driver_ops.c

@@ -310,6 +310,9 @@ static void wlan_hdd_remove(void)
 	cds_set_driver_loaded(false);
 	cds_set_unload_in_progress(true);
 
+	if (!cds_wait_for_external_threads_completion(__func__))
+		hdd_err("External threads are still active attempting driver unload anyway");
+
 	hdd_cnss_driver_unloading();
 
 	hif_ctx = cds_get_context(CDF_MODULE_ID_HIF);
@@ -354,7 +357,7 @@ static void wlan_hdd_shutdown(void)
 	    !WLAN_IS_EPPING_ENABLED(cds_get_conparam()))
 		hif_pktlogmod_exit(hif_ctx);
 
-	if (!cds_is_ssr_ready(__func__))
+	if (!cds_wait_for_external_threads_completion(__func__))
 		hdd_err("Host is not ready for SSR, attempting anyway");
 
 	if (!WLAN_IS_EPPING_ENABLED(cds_get_conparam())) {