device: inline nm_platform_ethtool_init_ring() function

nm_platform_ethtool_init_ring() only has one caller. It's simpler to
drop the function and implement it at the only place where it is needed.

Maybe there could be a place for a function to initialize NMEthtoolRingState,
one option after the other. However, at the moment there is only one
user, so don't implement it.

This fixes various minor issues:

- the function had a NMPlatform argument, although the argument
  is not used. Thus function merely operates on a NMEthtoolRingState
  instance and shouldn't have a nm_platform_*() name.

- nm_platform_ethtool_init_ring() returned a boolean, but all
  code paths (except assertion failures) returned success.

- as the function returned an error status, the caller was compelled
  to handle an error that could never happen.

- the option was specified by name, although we already have a more
  efficient way to express the option: the NMEthtoolID. Also, the
  caller already needed to resolve the name to the NMEthtoolID, so
  there was no need to again lookup the ID by name.

src/devices/nm-device.c

@@ -999,8 +999,12 @@ _ethtool_ring_set (NMDevice *self,
 
 	g_hash_table_iter_init (&iter, hash);
 	while (g_hash_table_iter_next (&iter, (gpointer *) &name, (gpointer *) &variant)) {
-		if (!nm_ethtool_optname_is_ring (name))
+		NMEthtoolID ethtool_id = nm_ethtool_id_get_by_name (name);
+		guint32 u32;
+
+		if (!nm_ethtool_id_is_ring (ethtool_id))
 			continue;
+
 		nm_assert (g_variant_is_of_type (variant, G_VARIANT_TYPE_UINT32));
 
 		if (!has_old) {
@@ -1014,12 +1018,23 @@ _ethtool_ring_set (NMDevice *self,
 			ring_new = ring_old;
 		}
 
-		if (!nm_platform_ethtool_init_ring (platform,
-		                                    &ring_new,
-		                                    name,
-		                                    g_variant_get_uint32 (variant))) {
-			_LOGW (LOGD_DEVICE, "ethtool: invalid ring setting %s", name);
-			return;
+		u32 = g_variant_get_uint32 (variant);
+
+		switch (ethtool_id) {
+		case NM_ETHTOOL_ID_RING_RX:
+			ring_new.rx_pending = u32;
+			break;
+		case NM_ETHTOOL_ID_RING_RX_JUMBO:
+			ring_new.rx_jumbo_pending = u32;
+			break;
+		case NM_ETHTOOL_ID_RING_RX_MINI:
+			ring_new.rx_mini_pending = u32;
+			break;
+		case NM_ETHTOOL_ID_RING_TX:
+			ring_new.tx_pending = u32;
+			break;
+		default:
+			nm_assert_not_reached ();
 		}
 	}
 
@@ -1056,8 +1071,6 @@ _ethtool_state_reset (NMDevice *self)
 		_ethtool_ring_reset (self, platform, ethtool_state);
 }
 
-
-
 static void
 _ethtool_state_set (NMDevice *self)
 {

src/platform/nm-platform.c

@@ -3252,41 +3252,6 @@ nm_platform_ethtool_get_link_ring (NMPlatform *self,
 	return nmp_utils_ethtool_get_ring (ifindex, ring);
 }
 
-gboolean
-nm_platform_ethtool_init_ring (NMPlatform *self,
-                               NMEthtoolRingState *ring,
-                               const char *option_name,
-                               guint32 value)
-{
-	NMEthtoolID ethtool_id;
-
-	g_return_val_if_fail (ring, FALSE);
-	g_return_val_if_fail (option_name, FALSE);
-
-	ethtool_id = nm_ethtool_id_get_by_name (option_name);
-
-	g_return_val_if_fail (nm_ethtool_id_is_ring (ethtool_id), FALSE);
-
-	switch (ethtool_id) {
-		case NM_ETHTOOL_ID_RING_RX:
-			ring->rx_pending = value;
-			break;
-		case NM_ETHTOOL_ID_RING_RX_JUMBO:
-			ring->rx_jumbo_pending = value;
-			break;
-		case NM_ETHTOOL_ID_RING_RX_MINI:
-			ring->rx_mini_pending = value;
-			break;
-		case NM_ETHTOOL_ID_RING_TX:
-			ring->tx_pending = value;
-			break;
-		default:
-			g_return_val_if_reached (FALSE);
-	}
-
-	return TRUE;
-}
-
 gboolean
 nm_platform_ethtool_set_ring (NMPlatform *self,
                               int ifindex,

src/platform/nm-platform.h

@@ -1975,11 +1975,6 @@ gboolean nm_platform_ethtool_get_link_ring (NMPlatform *self,
                                             int ifindex,
                                             NMEthtoolRingState *ring);
 
-gboolean nm_platform_ethtool_init_ring (NMPlatform *self,
-                                        NMEthtoolRingState *ring,
-                                        const char *option_name,
-                                        guint32 value);
-
 gboolean nm_platform_ethtool_set_ring (NMPlatform *self,
                                        int ifindex,
                                        const NMEthtoolRingState *ring);