On 2025-02-14 at 11:16:54, parvathi (parvathi@couthit.com) wrote:

From: Roger Quadros <redacted>

+static int icssm_prueth_probe(struct platform_device *pdev)
+{
+	struct device_node *eth0_node = NULL, *eth1_node = NULL;
+	struct device_node *eth_node, *eth_ports_node;
+	enum pruss_pru_id pruss_id0, pruss_id1;
+	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	struct prueth *prueth;
+	int i, ret;
+
+	np = dev->of_node;
+	if (!np)
+		return -ENODEV; /* we don't support non DT */
+
+	prueth = devm_kzalloc(dev, sizeof(*prueth), GFP_KERNEL);
+	if (!prueth)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, prueth);
+	prueth->dev = dev;
+	prueth->fw_data = device_get_match_data(dev);
+
+	eth_ports_node = of_get_child_by_name(np, "ethernet-ports");
+	if (!eth_ports_node)
+		return -ENOENT;
+
+	for_each_child_of_node(eth_ports_node, eth_node) {
+		u32 reg;
+
+		if (strcmp(eth_node->name, "ethernet-port"))
+			continue;
+		ret = of_property_read_u32(eth_node, "reg", &reg);
+		if (ret < 0) {
+			dev_err(dev, "%pOF error reading port_id %d\n",
+				eth_node, ret);
+		}
+
+		of_node_get(eth_node);
+
+		if (reg == 0) {
+			eth0_node = eth_node;
+			if (!of_device_is_available(eth0_node)) {
+				of_node_put(eth0_node);
+				eth0_node = NULL;
+			}
+		} else if (reg == 1) {
+			eth1_node = eth_node;
+			if (!of_device_is_available(eth1_node)) {
+				of_node_put(eth1_node);
+				eth1_node = NULL;
+			}

It depends on your DT, but is there any chance that more than once, we reach here in else case.
 { if (of_device_is_availabke(...) } ?

+		} else {
+			dev_err(dev, "port reg should be 0 or 1\n");
+		}
+	}
+
+	of_node_put(eth_ports_node);
+
+	/* At least one node must be present and available else we fail */
+	if (!eth0_node && !eth1_node) {
+		dev_err(dev, "neither port0 nor port1 node available\n");
+		return -ENODEV;
+	}
+
+	if (eth0_node == eth1_node) {
+		dev_err(dev, "port0 and port1 can't have same reg\n");
+		of_node_put(eth0_node);
+		return -ENODEV;
+	}
+
+	prueth->eth_node[PRUETH_MAC0] = eth0_node;
+	prueth->eth_node[PRUETH_MAC1] = eth1_node;

  ...
+

+	if (eth0_node) {
+		prueth->pru0 = pru_rproc_get(np, 0, &pruss_id0);
+		if (IS_ERR(prueth->pru0)) {
+			ret = PTR_ERR(prueth->pru0);
+			if (ret != -EPROBE_DEFER)
+				dev_err(dev, "unable to get PRU0: %d\n", ret);
+			goto put_pru;
+		}
+	}
+
+	if (eth1_node) {
+		prueth->pru1 = pru_rproc_get(np, 1, &pruss_id1);
+		if (IS_ERR(prueth->pru1)) {
+			ret = PTR_ERR(prueth->pru1);
+			if (ret != -EPROBE_DEFER)
+				dev_err(dev, "unable to get PRU1: %d\n", ret);
+			goto put_pru;
+		}
+	}
+
+	/* setup netdev interfaces */
+	if (eth0_node) {
+		ret = icssm_prueth_netdev_init(prueth, eth0_node);
+		if (ret) {
+			if (ret != -EPROBE_DEFER) {
+				dev_err(dev, "netdev init %s failed: %d\n",
+					eth0_node->name, ret);
+			}
+			goto put_pru;
+		}
+	}
+
+	if (eth1_node) {
+		ret = icssm_prueth_netdev_init(prueth, eth1_node);
+		if (ret) {
+			if (ret != -EPROBE_DEFER) {
+				dev_err(dev, "netdev init %s failed: %d\n",
+					eth1_node->name, ret);
+			}
+			goto netdev_exit;
+		}
+	}
+
+	/* register the network devices */
+	if (eth0_node) {
+		ret = register_netdev(prueth->emac[PRUETH_MAC0]->ndev);
+		if (ret) {
+			dev_err(dev, "can't register netdev for port MII0");
+			goto netdev_exit;
+		}
+
+		prueth->registered_netdevs[PRUETH_MAC0] =
+			prueth->emac[PRUETH_MAC0]->ndev;
+	}
+
+	if (eth1_node) {
+		ret = register_netdev(prueth->emac[PRUETH_MAC1]->ndev);
+		if (ret) {
+			dev_err(dev, "can't register netdev for port MII1");
+			goto netdev_unregister;
+		}
+
+		prueth->registered_netdevs[PRUETH_MAC1] =
+			prueth->emac[PRUETH_MAC1]->ndev;
+	}
+
+	if (eth1_node)
+		of_node_put(eth1_node);
+	if (eth0_node)
+		of_node_put(eth0_node);

nit: A function would be better than code duplication for eth0_node and eth1_node ?

+	return 0;
+
+netdev_unregister:
+	for (i = 0; i < PRUETH_NUM_MACS; i++) {
+		if (!prueth->registered_netdevs[i])
+			continue;
+		unregister_netdev(prueth->registered_netdevs[i]);
+	}
+
+netdev_exit:
+	for (i = 0; i < PRUETH_NUM_MACS; i++) {
+		eth_node = prueth->eth_node[i];
+		if (!eth_node)
+			continue;
+
+		icssm_prueth_netdev_exit(prueth, eth_node);
+	}
+
+put_pru:
+	if (eth1_node) {
+		if (prueth->pru1)
+			pru_rproc_put(prueth->pru1);
+		of_node_put(eth1_node);
+	}
+
+	if (eth0_node) {
+		if (prueth->pru0)
+			pru_rproc_put(prueth->pru0);
+		of_node_put(eth0_node);
+	}
+
+	return ret;
+}
+