Re: "Fix ATAPI transfer lengths" causes CD writing regression

Jens Axboe
2007-10-31T12:00:46Z

On Wed, Oct 31 2007, Alan Cox wrote:
> On Tue, 30 Oct 2007 19:21:29 +0000
> Daniel Drake <dsd@gentoo.org> wrote:
>
> > Alan Cox wrote:
> > > I would guess Brasero is issuing a command with the length of data
> > > wrongly set. In the old code that might well just produce errors of the
> > > "Umm wtf is this data left over for ?", with the new code the drive is
> > > likely to change state as it knows the transfer size and that will
> > > *correctly* cause an HSM error and what follows.
> > >
> > > Now the question is who gets the length wrong - Brasero or the ata
> > > translation code in libata
> >
> > Brasero does exactly the same as my test app which I attached to my last
> > mail. Is my test app wrong?
>
> Would need to double check the SCSI specificatons to be sure but I think
> you are asking for less data than the drive wishes to provide. You
> aren't allowed to do that with ATA.

ide-cd handles this by throwing the excess away, which I think is the
sane way to do this.

--
Jens Axboe