Deallocates device driver resources and can be used with the dd_open low function terminal (LFT) device driver interface to ensure exclusive access to a device.
The dd_close LFT device driver interface deallocates resources used by a device driver and can be used in conjunction with the dd_open LFT device driver to ensure exclusive access to a device.
| DevNo | Specifies the major and minor device numbers. |
| Chan | Specifies the channel number (multiplexed devices only). |
| Ext | Specifies the extension parameter for device-dependent functions. |
If successful, the dd_close device driver interface returns a value of 0. Otherwise, a value of 1 is returned and the errno global variable is set to indicate the error.