qcacld-3.0: Fix to restart SAP on preferred channel

qcacld-2.0 to qcacld-3.0 propagation

In some case when complete preferred channel list is unsafe,
SAP won't be able to pick any channel as operating channel.
This will lead to SAP start failure.

Fix this issue by making first channel from preferred channel
list as operating channel.

Change-Id: Id2bd177b15bd7089250a49019a9c751a691dac01
CRs-Fixed: 1026420

core/sap/src/sap_api_link_cntl.c

@@ -160,7 +160,16 @@ QDF_STATUS wlansap_scan_callback(tHalHandle hal_handle,
 				  __func__, scan_id);
 #endif
 		operChannel = sap_select_channel(hal_handle, sap_ctx, result);
+		if (!operChannel) {
+			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
+				"No channel was selected from preferred channel for Operating channel");
+
+			operChannel = sap_ctx->acs_cfg->start_ch;
 
+			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
+				"Selecting operating channel as starting channel from preferred channel list: %d",
+				operChannel);
+		}
 		sme_scan_result_purge(hal_handle, result);
 		break;
 
@@ -364,6 +373,16 @@ wlansap_pre_start_bss_acs_scan_callback(tHalHandle hal_handle, void *pcontext,
 		}
 #endif
 		oper_channel = sap_select_channel(hal_handle, sap_ctx, presult);
+		if (!oper_channel) {
+			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
+				"No channel was selected from preferred channel for Operating channel");
+
+			oper_channel = sap_ctx->acs_cfg->start_ch;
+
+			QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_INFO_HIGH,
+				"Selecting operating channel as starting channel from preferred channel list: %d",
+				oper_channel);
+		}
 		sme_scan_result_purge(hal_handle, presult);
 	}