Technical Reference: Kernel and Subsystems, Volume 2

CIO_HALT (Halt Device) entioctl Ethernet Device Handler Operation

Purpose

Note: This function is supported in AIX 5.1 and earlier only.

Ends a session with the Ethernet device handler.

Description

The CIO_HALT operation ends a session with the Ethernet device handler. The caller indicates the network ID to halt. This CIO_HALT operation corresponds with the CIO_START operation successfully issued with the specified network ID.

The CIO_HALT operation functions with an Ethernet High-Performance LAN adapter that has been correctly configured for use on a qualified network. Consult the network adapter specifications for more information on configuring the network adapter and network qualifications.

Data for the specified network ID is no longer received. Data already received for the specified network ID, before the CIO_HALT operation, is still passed up to a user-mode caller by the entselect and entread entry points. The rx_fn routine specified at open time passes data to a kernel-mode caller.

When a CIO_HALT operation has ended the last open session on a channel, the caller should then issue the entclose operation.

Note

If the caller has specified a multicast address, the caller first needs to issue the appropriate entioctl entry point to remove all the multicast addresses before issuing a CIO_HALT operation.

For a CIO_HALT operation, the arg parameter points to a session_blk structure. This structure is defined in the /usr/include/sys/comio.h file and contains the following fields:

Field	Description
`status`	There are two possible returned status values: CIO_OK CIO_NETID_INV
`netid`	Specifies the network ID. When IEEE 802.3 Ethernet is being used, the network ID is placed in the least significant byte of the `netid` field.

Execution Environment

A CIO_HALT operation can be called from the process environment only.

Return Values

The return codes for the CIO_HALT operation are:

Return Code	Description
EINVAL	Indicates the specified network ID is not in the table.
EBUSY	Indicates the open request was denied because the device was already open in Diagnostic mode or because the adapter was busy.
ENODEV	Indicates no such device exists.
ENXIO	Indicates an attempt to use an unconfigured device.

Related Information

The CIO_START entioctl Ethernet Device Handler Operation.

The entioctl entry point, entread entry point, entselect entry point.

Common Communications Status and Exception Codes in AIX 5L Version 5.2 Kernel Extensions and Device Support Programming Concepts.