Re: LANANA: To Pending Device Number Registrants

Richard Gooch
2001-05-16T20:55:12Z

H. Peter Anvin writes:
> Richard Gooch wrote:
> >
> > H. Peter Anvin writes:
> > > Richard Gooch wrote:
> > > > Argh! What I wrote in text is what I meant to say. The code didn't
> > > > match. No wonder people seemed to be missing the point. So the line of
> > > > code I actually meant was:
> > > > if (strcmp (buffer + len - 3, "/cd") != 0) {
> > >
> > > This is still a really bad idea. You don't want to tie this kind of
> > > things to the name.
> >
> > Why do you think it's a bad idea?
>
> Because you are now, once again, tying two things that are
> completely and utterly unrelated: device classification and device
> name. It breaks every time someone comes out with a new device
> which is "kind of like an old device, but not really," like
> CD-writers (which was kind-of-like WORM, kind-of-like CD-ROM) and
> DVD (kind-of-like CD)...

But all devices which export a CD-ROM interface will do so. So the
device node that is associated with the CD-ROM driver will export
CD-ROM semantics, and the trailing name will be "/cd".

Other interfaces a device exports, such as a CD-RW, appear as a
different device node ("generic" for SCSI, because we have no CD-RW
classification at this point).

My scheme works already, and works reliably. Nothing had to be done to
support the CD-ROM interface to CD-RW and DVD devices.

Regards,

Richard....
Permanent: rgooch@atnf.csiro.au
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