Re: 2.9test9-mm1 and DAO ATAPI cd-burning corrupt

Bill Davidsen
2003-11-13T12:04:09Z

On Tue, 11 Nov 2003, Linus Torvalds wrote:

>
> On Wed, 12 Nov 2003, Pascal Schmidt wrote:
> >
> > My guess would be that an MO drive needs a different way to find out
> > the capacity than a CD-ROM. After all, when using ide-scsi, it is the
> > sd driver and not sr that handles the drive. The rest of the problems
> > could be due to the wrong capacity information?
>
> Yes. That would explain a lot.
>
> The ide-scsi thing never uses "cdrom_get_last_written" crud. It just uses
> the regular READ_CAPACITY command (0x25).
>
> Which is what ide-cd.c will fall back to as well ("cdrom_read_capacity()")
> but I think it should _start_ with that rather than fall back on it.
> That's the simple case, after all.

Are there any cases when the last_written size is really what's wanted,
rather than the capacity? Such as unclosed multi-session iso9660, ufs, or
whatever else I'm ignoring?
>
> Does it work if you change the order of those two things in ide-cd.c (or
> just remove the call to "cdrom_get_last_written()" entirely, so that it
> always just does the sane thing).

For a read-only access, I think the size is what's written, while for
writing it's the physical size, I think. Does it need to be as complex as
having the order depend on the access mode? It seems that a size of zero
is correct for a read access to an unwritten media.

--
bill davidsen <davidsen@tmr.com>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.