sfc: Split PTP multicast filter insertion/removal out of efx_ptp_{start,stop}()

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

drivers/net/ethernet/sfc/ptp.c

@@ -755,13 +755,27 @@ static inline void efx_ptp_process_rx(struct efx_nic *efx, struct sk_buff *skb)
 	local_bh_enable();
 }
 
-static int efx_ptp_start(struct efx_nic *efx)
+static void efx_ptp_remove_multicast_filters(struct efx_nic *efx)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+
+	if (ptp->rxfilter_installed) {
+		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+					  ptp->rxfilter_general);
+		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+					  ptp->rxfilter_event);
+		ptp->rxfilter_installed = false;
+	}
+}
+
+static int efx_ptp_insert_multicast_filters(struct efx_nic *efx)
 {
 	struct efx_ptp_data *ptp = efx->ptp_data;
 	struct efx_filter_spec rxfilter;
 	int rc;
 
-	ptp->reset_required = false;
+	if (ptp->rxfilter_installed)
+		return 0;
 
 	/* Must filter on both event and general ports to ensure
 	 * that there is no packet re-ordering.
@@ -794,23 +808,37 @@ static int efx_ptp_start(struct efx_nic *efx)
 		goto fail;
 	ptp->rxfilter_general = rc;
 
+	ptp->rxfilter_installed = true;
+	return 0;
+
+fail:
+	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
+				  ptp->rxfilter_event);
+	return rc;
+}
+
+static int efx_ptp_start(struct efx_nic *efx)
+{
+	struct efx_ptp_data *ptp = efx->ptp_data;
+	int rc;
+
+	ptp->reset_required = false;
+
+	rc = efx_ptp_insert_multicast_filters(efx);
+	if (rc)
+		return rc;
+
 	rc = efx_ptp_enable(efx);
 	if (rc != 0)
-		goto fail2;
+		goto fail;
 
 	ptp->evt_frag_idx = 0;
 	ptp->current_adjfreq = 0;
-	ptp->rxfilter_installed = true;
 
 	return 0;
 
-fail2:
-	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
-				  ptp->rxfilter_general);
 fail:
-	efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
-				  ptp->rxfilter_event);
-
+	efx_ptp_remove_multicast_filters(efx);
 	return rc;
 }
 
@@ -826,13 +854,7 @@ static int efx_ptp_stop(struct efx_nic *efx)
 
 	rc = efx_ptp_disable(efx);
 
-	if (ptp->rxfilter_installed) {
-		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
-					  ptp->rxfilter_general);
-		efx_filter_remove_id_safe(efx, EFX_FILTER_PRI_REQUIRED,
-					  ptp->rxfilter_event);
-		ptp->rxfilter_installed = false;
-	}
+	efx_ptp_remove_multicast_filters(efx);
 
 	/* Make sure RX packets are really delivered */
 	efx_ptp_deliver_rx_queue(&efx->ptp_data->rxq);