Find an extended capability
int pci_find_ext_capability(struct pci_dev * dev, int cap);
dev
PCI device to query
cap
capability code
Returns the address of the requested extended capability structure within the device's PCI configuration space or 0 if the device does not support it. Possible values for cap:
PCI_EXT_CAP_ID_ERR Advanced Error Reporting PCI_EXT_CAP_ID_VC Virtual Channel PCI_EXT_CAP_ID_DSN Device Serial Number PCI_EXT_CAP_ID_PWR Power Budgeting