Re: [PATCH] make ide-cd handle non-2kB sector sizes

From: Maciej W. Rozycki
Date: Fri Jan 23 2004 - 17:12:09 EST


On Fri, 23 Jan 2004, Pascal Schmidt wrote:

> > So that's just opposite to what ide-cd does, but I think ide-cd should be
> > limited to CD-like devices with their all properties (oddities).
>
> When I brought up the issue a few months back, the consensus was to
> use ide-cd, not ide-floppy.

Interesting. I would consider ide-floppy (despite its somewhat
inadequate name) the driver for all ATAPI disks as opposed to ATA disks
that use ide-disk. CD-like devices are much different, supporting such
alien to disk devices entities like tracks or audio reading or playing.

BTW, does ide-cd support partition tables yet? You typically want them
for MO disks if you want to transport data to/from other OSes or simply
because their space is big enough to create separate filesystems for
certain applications. Or perhaps swap space even. ;-)

> > Specifically you can do random writes to an MO disk, perhaps even format
> > it, which is usually not the case with CDs.
>
> ide-cd also handles DVD-RAM, which can also handle random writes.

Well, an exception rather than a rule. ;-)

> > BTW, what does ide-scsi say of the device type for the MO: is it "CD-ROM"
> > or "Direct-Access" or anything else? I used an MO drive (a SCSI one --
> > nobody was crazy enough to think of an ATAPI interface for that kinds of
> > devices at that time) for a short while under Linux once and it used to be
> > the latter, with sd, not sr being the appropriate driver.
>
> On 2.4:
>
> scsi0 : SCSI host adapter emulation for IDE ATAPI devices
> Vendor: FUJITSU Model: M25-MCC3064AP Rev: 0051
> Type: Optical Device ANSI SCSI revision: 02
>
> And yes, this uses the sd driver.

I see -- that's reasonable. And I can't understand the proposed
inconsistency with drivers -- why it should be a CD when being an ATAPI
device and a disk when being a SCSI one? After all SCSI has a separate
driver for CDs as well...

Maciej

--
+ Maciej W. Rozycki, Technical University of Gdansk, Poland +
+--------------------------------------------------------------+
+ e-mail: macro@xxxxxxxxxxxxx, PGP key available +
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