Re: Dont understand hdc=ide-scsi behaviour.

From: Brad Hards (
Date: Fri Sep 20 2002 - 01:46:00 EST

Hash: SHA1

On Fri, 20 Sep 2002 07:08, Reg Clemens wrote:
> I dont understand the behaviour of kernel 2.4.18 (and probably all others)
> when I put the line
> hdc=ide-scsi
> on the load line.
> I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead
> get it for BOTH hdc and hdd, the cdwriter and the zip drive.
> After starting this way (with hdc=ide-scsi), I find that
> /dev/cdrom2 -> /dev/scd0
> and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)
There are two slightly different things happening, I think.

1. When you say hdc=ide-scsi, you are telling the IDE system that you don't
want to use the normal IDE interfaces to userland (such as ide-cdrom), but
instead want all access to this device to be accessed through the SCSI
midlayer (and associated SCSI interfaces, like the sg and scd drivers). So
ide-scsi becomes the driver, instead of ide-cdrom. You should be able to see
this in /proc/ide/hdc/driver

2. ide-scsi is greedy, and will grab any IDE device without a driver. ATAPI
floppy devices (hopefully) like your zip drive need the IDE floppy device
driver, which is probably not loaded. What does CONFIG_BLK_DEV_IDEFLOPPY
equal in your kernel config?

> I would EXPECT to get to them via /dev/hdd1 or /dev/hdd4.
And you will, with the right driver loaded :-)

> Did I miss something or is this a bug????
If you load ide-floppy before ide-scsi, and it still doesn't work, then there
is a bug.

- -- 22-25Jan2003. Perth, Australia. Birds in Black.
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

This archive was generated by hypermail 2b29 : Mon Sep 23 2002 - 22:00:29 EST