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'new_bus->irq[phydev->mdio.addr]' drivers/net/ethernet/stmicro/stmmac/stmmac_mdio.c 577 int stmmac_mdio_register(struct net_device *ndev) 578 { 579 int err = 0; 580 struct mii_bus *new_bus; 581 struct stmmac_priv *priv = netdev_priv(ndev); 582 struct stmmac_mdio_bus_data *mdio_bus_data = priv->plat->mdio_bus_data; 583 struct device_node *mdio_node = priv->plat->mdio_node; 584 struct device *dev = ndev->dev.parent; 585 struct fwnode_handle *fixed_node; 586 struct fwnode_handle *fwnode; 587 struct phy_device *phydev; 588 int max_addr; 589 590 if (!mdio_bus_data) 591 return 0; 592 593 stmmac_mdio_bus_config(priv); 594 595 new_bus = mdiobus_alloc(); 596 if (!new_bus) 597 return -ENOMEM; 598 599 if (mdio_bus_data->irqs) 600 memcpy(new_bus->irq, mdio_bus_data->irqs, sizeof(new_bus->irq)); 601 602 new_bus->name = "stmmac"; 603 604 if (priv->plat->has_xgmac) { 605 new_bus->read = &stmmac_xgmac2_mdio_read_c22; 606 new_bus->write = &stmmac_xgmac2_mdio_write_c22; 607 new_bus->read_c45 = &stmmac_xgmac2_mdio_read_c45; 608 new_bus->write_c45 = &stmmac_xgmac2_mdio_write_c45; 609 610 if (priv->synopsys_id < DWXGMAC_CORE_2_20) { 611 /* Right now only C22 phys are supported */ 612 max_addr = MII_XGMAC_MAX_C22ADDR + 1; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ max_addr set here. This is the line which gave me pause. MII_XGMAC_MAX_C22ADDR is 3, but why do we do a "+ 1"? 613 614 /* Check if DT specified an unsupported phy addr */ 615 if (priv->plat->phy_addr > MII_XGMAC_MAX_C22ADDR) 616 dev_err(dev, "Unsupported phy_addr (max=%d)\n", 617 MII_XGMAC_MAX_C22ADDR); 618 } else { 619 /* XGMAC version 2.20 onwards support 32 phy addr */ 620 max_addr = PHY_MAX_ADDR; ^^^^^^^^^^^^^^^^^^^^^^^^ 621 } 622 } else { 623 new_bus->read = &stmmac_mdio_read_c22; 624 new_bus->write = &stmmac_mdio_write_c22; 625 if (priv->plat->has_gmac4) { 626 new_bus->read_c45 = &stmmac_mdio_read_c45; 627 new_bus->write_c45 = &stmmac_mdio_write_c45; 628 } 629 630 max_addr = PHY_MAX_ADDR; ^^^^^^^^^^^^^^^^^^^^^^^ 631 } 632 633 if (mdio_bus_data->needs_reset) 634 new_bus->reset = &stmmac_mdio_reset; 635 636 snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s-%x", 637 new_bus->name, priv->plat->bus_id); 638 new_bus->priv = ndev; 639 new_bus->phy_mask = mdio_bus_data->phy_mask | mdio_bus_data->pcs_mask; 640 new_bus->parent = priv->device; 641 642 err = of_mdiobus_register(new_bus, mdio_node); 643 if (err == -ENODEV) { 644 err = 0; 645 dev_info(dev, "MDIO bus is disabled\n"); 646 goto bus_register_fail; 647 } else if (err) { 648 dev_err_probe(dev, err, "Cannot register the MDIO bus\n"); 649 goto bus_register_fail; 650 } 651 652 /* Looks like we need a dummy read for XGMAC only and C45 PHYs */ 653 if (priv->plat->has_xgmac) 654 stmmac_xgmac2_mdio_read_c45(new_bus, 0, 0, 0); 655 656 /* If fixed-link is set, skip PHY scanning */ 657 fwnode = priv->plat->port_node; 658 if (!fwnode) 659 fwnode = dev_fwnode(priv->device); 660 661 if (fwnode) { 662 fixed_node = fwnode_get_named_child_node(fwnode, "fixed-link"); 663 if (fixed_node) { 664 fwnode_handle_put(fixed_node); 665 goto bus_register_done; 666 } 667 } 668 669 if (priv->plat->phy_node || mdio_node) 670 goto bus_register_done; 671 672 phydev = phy_find_first(new_bus); 673 if (!phydev || phydev->mdio.addr > max_addr) { This is an unpublished check because it assumes that every > comparison is off by one unless proven otherwise. In this case max_addr is PHY_MAX_ADDR (32) and phydev->mdio.addr is also 32. 674 dev_warn(dev, "No PHY found\n"); 675 err = -ENODEV; 676 goto no_phy_found; 677 } 678 679 /* 680 * If an IRQ was provided to be assigned after 681 * the bus probe, do it here. 682 */ 683 if (!mdio_bus_data->irqs && mdio_bus_data->probed_phy_irq > 0) { --> 684 new_bus->irq[phydev->mdio.addr] = mdio_bus_data->probed_phy_irq; ^^^^^^^^^^^^^^^^^ Then this will corrupt memory. 685 phydev->irq = mdio_bus_data->probed_phy_irq; 686 } 687 688 /* 689 * If we're going to bind the MAC to this PHY bus, and no PHY number 690 * was provided to the MAC, use the one probed here. 691 */ 692 if (priv->plat->phy_addr == -1) 693 priv->plat->phy_addr = phydev->mdio.addr; 694 695 phy_attached_info(phydev); 696 697 bus_register_done: 698 priv->mii = new_bus; 699 700 return 0; 701 702 no_phy_found: 703 mdiobus_unregister(new_bus); 704 bus_register_fail: 705 mdiobus_free(new_bus); 706 return err; 707 } regards, dan carpenter