pci_rescan_bus()在Linux中不会重新扫描PCI总线 [英] pci_rescan_bus() doesn't rescan PCI bus in Linux

问题描述

我试图借助 pci_rescan_bus()内核功能在我自己的内核驱动程序中重新扫描PCI总线，但我看不到它的功能相同.

I am trying to rescan PCI bus in my own kernel driver with the help of pci_rescan_bus() kernel function but I do not see it is functioning same.

如果我尝试通过运行以下命令在用户空间中执行相同操作，则会看到重新扫描:

If I try to do same from user space by running following command, I see that rescanning happens:

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:

I am trying to re-initialize my ethernet ports which sit on PCI bus. Below is the code I am using for now:

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, 0x8168, pci_eth_dev01);
if (pci_eth_dev02 != NULL)
    dev_info(&info->client->dev, "class - %2X\tbus number - %d\n", 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 pci_rescan_bus()函数调用中获得了 2 作为返回值.

I get 2 as a return value from pci_rescan_bus() function call.

我在这里做错什么了吗?

Am I doing anything wrong here?

推荐答案

发现 pci_rescan_bus(pci_eth_dev02-> bus-> parent)是正确的调用方式，而不是 pci_rescan_bus(pci_eth_dev02-> bus)，只需稍加修改，这就是我当前的实现方式，

Found that pci_rescan_bus(pci_eth_dev02->bus->parent) is the right call to make instead of pci_rescan_bus(pci_eth_dev02->bus) and with little more modifications this is how my current implementation looks like,

    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,
                                       REALTEK_ETH_DEVICE_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, "Device Class - 0x%X\tPCI Bus Number - %d\n",
                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;
    }

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