Intel Extensible Firmware Interface - Manual (Page 260)

Extensible Firmware Interface Specification
9-18 12/01/02 Version 1.10
EFI_DRIVER_BINDING_PROTOCOL.Stop()
Summary
Stops a device controller or a bus controller. The Start() and Stop() services of the
EFI_DRIVER_BINDING_PROTOCOL mirror each other.
Prototype
typedef
EFI_STATUS
(EFIAPI *EFI_DRIVER_BINDING_PROTOCOL_STOP) (
IN EFI_DRIVER_BINDING_PROTOCOL
*This,
IN EFI_HANDLE ControllerHandle,
IN UINTN NumberOfChildren,
IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
);
Parameters
This A pointer to the EFI_DRIVER_BINDING_PROTOCOL
instance. Type EFI_DRIVER_BINDING_PROTOCOL is
defined in section 9.1.
ControllerHandle A handle to the device being stopped. The handle must support
a bus specific I/O protocol for the driver to use to stop the
device.
NumberOfChildren The number of child device handles in ChildHandleBuffer .
ChildHandleBuffer An array of child handles to be freed. May be NULL if
NumberOfChildren is 0.
Description
This function performs different operations depending on the parameter NumberOfChildren . If
NumberOfChildren is not zero, then the driver specified by This is a bus driver, and it is
being requested to free one or more of its child handles specified by NumberOfChildren and
ChildHandleBuffer . If all of the child handles are freed, then EFI_SUCCESS is returned. If
NumberOfChildren is zero, then the driver specified by This is either a device driver or a bus
driver, and it is being requested to stop the controller specified by ControllerHandle . If
ControllerHandle is stopped, then EFI_SUCCESS is returned. In either case, this function is
required to undo what was performed in Start() . Whatever resources are allocated in
Start() must be freed in Stop() . For example, every AllocatePool() ,
AllocatePages() , OpenProtocol() , and InstallProtocolInterface() in
Start() must be matched with a FreePool() , FreePages() , CloseProtocol() , and
UninstallProtocolInterface() in Stop() .