Arla 0.42-RC2

[Rick C. Petty]

On Tue, Apr 04, 2006 at 12:28:12PM -0400, Jeffrey Hutzelman wrote:
> 
> Then it should return ENXIO ("no such device or address"), not ENODEV ("no 
> such device").  The distinction is subtle, but
> 
> - ENODEV means "there is no driver to handle that device node"
> - ENXIO means "the driver exists, but the device does not"
> - EIO means "the device exists, but we had trouble using it"

The FreeBSD intro(2) manpage describes it even better:

 6 ENXIO Device not configured.  Input or output on a special file
	referred to a device that did not exist, or made a request beyond
	the limits of the device.  This error may also occur when, for
	example, a tape drive is not online or no disk pack is loaded on
	a drive.

 19 ENODEV Operation not supported by device.  An attempt was made to
	apply an inappropriate function to a device, for example, trying
	to read a write-only device such as a printer.

 5 EIO Input/output error.  Some physical input or output error occurred.
	This error will not be reported until a subsequent operation on
	the same file descriptor and may be lost (over written) by any
	subsequent errors.


-- Rick C. Petty