问题
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.
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
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);
I get 2
as a return value from pci_rescan_bus()
function call.
Am I doing anything wrong here?
回答1:
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;
}
来源:https://stackoverflow.com/questions/64549023/pci-rescan-bus-doesnt-rescan-pci-bus-in-linux