pci_rescan_bus不会在Linux中重新扫描PCI总线

问题描述

我正在尝试借助pci_rescan_bus()内核功能在自己的内核驱动程序中重新扫描PCI总线，但是我看不到它的功能。

如果我尝试通过运行以下命令从用户空间执行相同操作，则会看到重新扫描：

echo 1 > /sys/devices/pci0000:00/0000:00:14.1/rescan

我正在尝试重新初始化位于PCI总线上的以太网端口。下面是我现在使用的代码：

struct pci_dev *pci_eth_dev01,*pci_eth_dev02 = NULL;
pci_eth_dev01 = pci_get_device(0x10ec,0x8168,NULL);
if (pci_eth_dev01 != NULL)
    dev_info(&info->client->dev,"class - %2X\tbus number - %d\n",pci_eth_dev01->class,pci_eth_dev01->bus->number);
else
    dev_info(&info->client->dev,"Error retreiving pci device\n");

pci_eth_dev02 = pci_get_device(0x10ec,pci_eth_dev01);
if (pci_eth_dev02 != NULL)
    dev_info(&info->client->dev,pci_eth_dev02->class,pci_eth_dev02->bus->number);
else
    dev_info(&info->client->dev,"Error retreiving pci device\n");

pci_stop_and_remove_bus_device(pci_eth_dev02);
pci_remove_bus(pci_eth_dev02->bus);

unsigned int ret = 0;
pci_lock_rescan_remove();
ret = pci_rescan_bus(pci_eth_dev02->bus);
pci_unlock_rescan_remove();
dev_info(&info->client->dev,"ret from pci_rescan_bus - %d\n",ret);

我从2函数调用中获得了pci_rescan_bus()作为返回值。

我在这里做错什么了吗？

解决方法

发现pci_rescan_bus(pci_eth_dev02->bus->parent)是正确的选择，而不是pci_rescan_bus(pci_eth_dev02->bus)，这是我当前的实现方式，只需稍加修改即可，

    static bool re_initialize_eth_ports(struct supercap_info *info)
    {
        struct pci_dev *pci_eth_dev01 = NULL;
        struct pci_dev *pci_eth_dev02 = NULL;
    
        // Get PCI device structures since ethernet ports sit on PCI bus.
        pci_eth_dev01 = pci_get_device(REALTEK_ETH_VENDOR_ID,REALTEK_ETH_DEVICE_ID,NULL);
        pci_eth_dev02 = pci_get_device(REALTEK_ETH_VENDOR_ID,pci_eth_dev01);
        if (!pci_eth_dev01 || !pci_eth_dev02) {
            dev_err(&info->client->dev,"Error retrieving PCI device structure\n");
            return false;
        }
        dev_dbg(&info->client->dev,"Device Class - 0x%X\tPCI Bus Number - %d\n",pci_eth_dev01->class,pci_eth_dev01->bus->number);
        dev_dbg(&info->client->dev,pci_eth_dev02->class,pci_eth_dev02->bus->number);
        // Remove PCI bus devices from the device lists.
        pci_stop_and_remove_bus_device_locked(pci_eth_dev01);
        pci_stop_and_remove_bus_device_locked(pci_eth_dev02);
        // Acquire a mutex lock before re-scanning PCI buses.
        pci_lock_rescan_remove();
        // Re-scan PCI parent buses for devices.
        pci_rescan_bus(pci_eth_dev01->bus->parent);
        pci_rescan_bus(pci_eth_dev02->bus->parent);
        // Release a mutex lock.
        pci_unlock_rescan_remove();
        return true;
    }