Re: [IDE] trying to make MO drive work with ide-floppy/ide-cd

[Jens Axboe <axboe@suse.de>]

On Tue, May 06 2003, Pascal Schmidt wrote:
> On 6 May 2003, Alan Cox wrote:
> 
> > I'm not aware of any plans to make ide-floppy handle that disk, or reasons
> > you would want to use ide floppy in 2.5 not the ide-cd layer (which does
> > now handle writable devices I believe).
> 
> Okay, didn't think of that, so I now tried using ide-cd for the MO drive
> (2.5.68+bkcvs). I still had to patch ide-probe.c, just passing "hde=cdrom" 
> did not do what I wanted. ;)

Uh nasty :)

> Now I get the following at bootup:
> 
> hde: FUJITSU MCC3064AP, ATAPI OPTICAL drive
> hde: set_drive_speed_status: status=0x51 { DriveReady SeekComplete Error }
> hde: set_drive_speed_status: error=0x04
> Uniform CD-ROM driver Revision: 3.12
> end_request: I/O error, dev hde, sector 0
> hde: packet command error: status=0x51 { DriveReady SeekComplete Error }
> hde: packet command error: error=0x50
> end_request: I/O error, dev hde, sector 0
> ATAPI device hde:
>   Error: Illegal request -- (Sense key=0x05)
>   Invalid field in command packet -- (asc=0x24, ascq=0x00)
>   The failed "Mode Sense 10" packet command was: 
>   "5a 00 2a 00 00 00 00 00 18 00 00 00 00 00 00 00 "
>   Error in command data byte 8800
> hde: packet command error: status=0x51 { DriveReady SeekComplete Error }
> hde: packet command error: error=0x50
> end_request: I/O error, dev hde, sector 0
> ATAPI device hde:
>   Error: Illegal request -- (Sense key=0x05)
>   Invalid field in command packet -- (asc=0x24, ascq=0x00)
>   The failed "Mode Sense 10" packet command was: 
>   "5a 00 2a 00 00 00 00 00 18 00 00 00 00 00 00 00 "
>   Error in command data byte 8800
> end_request: I/O error, dev hde, sector 0

It barfs at a lot of commands, not surprisingly. ide-cd really has no
concept of devices other than cd/dvd.

> This doesn't look encouraging. However, the MO drive sort of works:
> 
> # mount -t ext2 /dev/hde /mnt/mo
> mount: block device /dev/hde is write-protected, mounting read-only
> 
> The disk gets mounted and reading works just fine. No write support,
> though. To reiterate, everything works under 2.4 using ide-scsi.

You need to patch cdrom.c as well:

	if ((fp->f_mode & FMODE_WRITE) && !CDROM_CAN(CDC_DVD_RAM))
		return -EROFS;

> What can I do to help get this drive supported under 2.5/ide-cd?

I'm tempted to say ide-scsi + sd, but that goes against my principles...
It shouldn't be too much work to make ide-cd work gracefully.

-- 
Jens Axboe