qcacld-3.0: Fix the channel switch to 2.4Ghz after pre-cac

In case of pre-cac as part of pre-cac vdev delete the whole
mac_ctx->sap is zero in sap_clear_global_dfs_param() and thus the
loop for mac_ctx->sap.sapCtxList always return null sap ctx. Due
to this if radar is dedected on the original SAP, the vdev switch
to new channel is ignored.

Also in case of radar detection if SAP moves to 2.4ghz, the HW mode
change is not attempted and thus vdev restart fails on 2.4ghz if HW
mode is not DBS.

Thus dont reset the mac_ctx->sap in sap_clear_global_dfs_param() and
add check if HW mode change is required when channel change due to
Radar detection.

Change-Id: Id44a0ddbbb20035412b0c039c12f7f59f2c37f1a
CRs-Fixed: 2753029

core/sap/src/sap_fsm.c

@@ -1083,7 +1083,6 @@ static QDF_STATUS sap_clear_global_dfs_param(mac_handle_t mac_handle)
 	}
 	mac_ctx->sap.SapDfsInfo.cac_state = eSAP_DFS_DO_NOT_SKIP_CAC;
 	sap_cac_reset_notify(mac_handle);
-	qdf_mem_zero(&mac_ctx->sap, sizeof(mac_ctx->sap));
 
 	return QDF_STATUS_SUCCESS;
 }
@@ -1170,11 +1169,9 @@ QDF_STATUS sap_clear_session_param(mac_handle_t mac_handle,
 		QDF_MAX_NO_OF_MODE;
 	sap_clear_global_dfs_param(mac_handle);
 	sap_free_roam_profile(&sapctx->csr_roamProfile);
+	sap_err("Set sapCtxList null for session %d", sapctx->sessionId);
 	qdf_mem_zero(sapctx, sizeof(*sapctx));
 	sapctx->sessionId = WLAN_UMAC_VDEV_ID_MAX;
-	QDF_TRACE(QDF_MODULE_ID_SAP, QDF_TRACE_LEVEL_DEBUG,
-		"%s: Initializing State: %d, sap_ctx value = %pK", __func__,
-		sapctx->fsm_state, sapctx);
 
 	return QDF_STATUS_SUCCESS;
 }
@@ -2680,6 +2677,34 @@ static inline QDF_STATUS
 sap_fsm_send_csa_restart_req(struct mac_context *mac_ctx,
 			     struct sap_context *sap_ctx)
 {
+	QDF_STATUS status;
+
+	status = policy_mgr_check_and_set_hw_mode_for_channel_switch(
+				mac_ctx->psoc, sap_ctx->sessionId,
+				mac_ctx->sap.SapDfsInfo.target_chan_freq,
+				POLICY_MGR_UPDATE_REASON_CHANNEL_SWITCH_SAP);
+
+	/*
+	 * If hw_mode_status is QDF_STATUS_E_FAILURE, mean HW
+	 * mode change was required but driver failed to set HW
+	 * mode so ignore CSA for the channel.
+	 */
+	if (status == QDF_STATUS_E_FAILURE) {
+		sap_err("HW change required but failed to set hw mode");
+		return status;
+	}
+
+	/*
+	 * If hw_mode_status is QDF_STATUS_SUCCESS mean HW mode
+	 * change was required and was successfully requested so
+	 * the channel switch will continue after HW mode change
+	 * completion.
+	 */
+	if (QDF_IS_STATUS_SUCCESS(status)) {
+		sap_info("Channel change will continue after HW mode change");
+		return QDF_STATUS_SUCCESS;
+	}
+
 	return sme_csa_restart(mac_ctx, sap_ctx->sessionId);
 }