Re: PATCH: cdrecord: avoiding scsi device numbering for ide devices

Måns Rullgård
2004-08-05T17:32:36Z

Wakko Warner <wakko@animx.eu.org> writes:

> Please do keep me CCd
>
>> >ATA method is misnamed, it's really SG_IO that is used. And you want to
>> >use that regardless of the device type, SCSI or ATAPI. There's no such
>> >thing as an ATA burner, and there's no need to differentiate between
>> >SCSI or ATAPI CD-ROM's when burning - SG_IO is the method to use. So
>> >forget browsing /proc/ide and other hacks.
>>
>> I am sorry but as Linux already has 6 different interfaces for sending
>> Generic SCSI commands and thus, we are running out of names.
>>
>> Let me give you an advise: consolidate Linux so that is does only need
>> /dev/sg and fix the bugs in ide-scsi instead of constantly inventing new
>> unneeded interfaces.
>
> I'd like to take this and stretch it some.
>
> First, I don't know what would be involved in doing this or if it's even
> doable (but I'd think it is). I would like to see this happen, however, I
> understand that it may or may not.
>
> Why do we have a seperate subsystem for scsi and ide, but not usb storage
> devices? What I mean is that usb-storage is a scsi adapter that attaches
> usb disks to the scsi layer. I know about ide-scsi, but that's like a
> bridge that probably could be removed entirely.
>
> Now here's what I'm thinking:
>
> 1) remove the IDE subsystem entirely (keeping the IDE drivers). This will
> eliminate the need for /dev/hd* devices and ide-scsi.
>
> 2) rename the scsi subsystem to something more generic, like disk subsystem
> (I realize that scsi can handle more than disks, like tapes, scanners, I
> even once saw a scsi ethernet adapter)
>
> 3) port all of the IDE drivers to be like a scsi adapter driver (ie fix piix
> to function similar to say aic7xxx). To handle the fact of multiple
> interfaces on the controller (primary/secondary connectors on the board, 4
> devices total) to be seperate scsi buses. On each bus, you'll only have 2
> IDs, 0 and 1 (corresponding to master and slave).
>
> 4) All access to the device will be like a scsi device. For IDE devices, if
> needed, the driver (ie piix) can translate the request.

Isn't this what libata does with SATA disks? SATA is already standard
in new machines, and within a couple of years parallel ATA is like to
be mostly obsolete.

--
Måns Rullgård
mru@kth.se