Man page 9 : pci_reset_function

pci_reset_function - quiesce and reset a PCI device function

int pci_reset_function(struct pci_dev *  dev );

dev
    PCI device to reset

Some devices allow an individual function to be reset without affecting other functions in the same device. The PCI device must be responsive to PCI config space in order to use this function.

This function does not just reset the PCI portion of a device, but clears all the state associated with the device. This function differs from __pci_reset_function in that it saves and restores device state over the reset.

Returns 0 if the device function was successfully reset or negative if the device doesnAqt support resetting a single function.