qcacld-3.0: Change sap Channel if unsafe during cac

While doing CAC for moving SAP to DFS channel, channel
avoid event can be received. While in CAC is going on,
the current sap channel is not updated and remains the
channel on which sap was before CAC. It is only updated
after CSA. So, when channel avoid event is received,
it is checked against the previous frequency and hence,
no action is taken as the previous frequency is part of
safe channel. This results in sap starting and remaining
in Unsafe channel.
As, a fix when sap starts after CSA, check for unsafe
channel and if the sap frequency is unsafe then restart
it to another channel.

Change-Id: I910b80fe87fc149f25e84383b128a5e5c9d269e4
CRs-Fixed: 3287239

core/sap/src/sap_fsm.c

@@ -3536,6 +3536,84 @@ static void sap_check_and_update_vdev_ch_params(struct sap_context *sap_ctx)
 		  sap_ctx->ch_params.ch_width);
 }
 
+static qdf_freq_t sap_get_safe_channel_freq(struct sap_context *sap_ctx)
+{
+	qdf_freq_t freq;
+
+	freq = wlan_pre_cac_get_freq_before_pre_cac(sap_ctx->vdev);
+	if (!freq)
+		freq = sap_random_channel_sel(sap_ctx);
+
+	sap_debug("new selected freq %d as target chan as current freq unsafe %d",
+		  freq, sap_ctx->chan_freq);
+
+	return freq;
+}
+
+/**
+ * sap_fsm_send_csa_restart_req() - send csa start event
+ * @mac_ctx: mac ctx
+ * @sap_ctx: SAP context
+ *
+ * Return: QDF_STATUS
+ */
+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);
+}
+
+/**
+ * sap_fsm_handle_check_safe_channel() - handle channel Avoid event event during
+ *                                       cac
+ * @mac_ctx: global MAC context
+ *
+ * Return: QDF_STATUS
+ */
+static void sap_fsm_handle_check_safe_channel(struct mac_context *mac_ctx,
+					      struct sap_context *sap_ctx)
+{
+	if (policy_mgr_is_safe_channel(mac_ctx->psoc, sap_ctx->chan_freq))
+		return;
+
+	mac_ctx->sap.SapDfsInfo.target_chan_freq =
+					sap_get_safe_channel_freq(sap_ctx);
+	/*
+	 * The selected channel is not safe channel. Hence,
+	 * change the sap channel to a safe channel.
+	 */
+	sap_fsm_send_csa_restart_req(mac_ctx, sap_ctx);
+}
+
 /**
  * sap_fsm_state_starting() - utility function called from sap fsm
  * @sap_ctx: SAP context
@@ -3660,6 +3738,13 @@ static QDF_STATUS sap_fsm_state_starting(struct sap_context *sap_ctx,
 				wlansap_start_beacon_req(sap_ctx);
 			}
 		}
+		/*
+		 * During CSA, it might be possible that ch avoidance event to
+		 * avoid the sap frequency is received. So, check after CSA,
+		 * whether sap frequency is safe if not restart sap to a safe
+		 * channel.
+		 */
+		sap_fsm_handle_check_safe_channel(mac_ctx, sap_ctx);
 	} else if (msg == eSAP_MAC_START_FAILS ||
 		 msg == eSAP_HDD_STOP_INFRA_BSS) {
 			qdf_status = sap_fsm_handle_start_failure(sap_ctx, msg,
@@ -3694,48 +3779,6 @@ static QDF_STATUS sap_fsm_state_starting(struct sap_context *sap_ctx,
 	return qdf_status;
 }
 
-/**
- * sap_fsm_send_csa_restart_req() - send csa start event
- * @mac_ctx: mac ctx
- * @sap_ctx: SAP context
- *
- * Return: QDF_STATUS
- */
-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);
-}
-
 /**
  * sap_fsm_state_started() - utility function called from sap fsm
  * @sap_ctx: SAP context