Re: Oops with 2.2.13pre17 and ide-scsi

Wakko Warner (wakko@animx.eu.org)
Tue, 19 Oct 1999 07:15:43 -0400


> > > > This happens when you compile in "probe all luns" with ide-scsi enabled.
> > > > Disable "probe all luns" and the 8 targed ids will go away. Guaranteed.
> > > > It should probably be counted as an ide-scsi bug? (Do any ide devices
> > > > legitimately have more than one ide-scsi lun?)
> > > Isn't there a way to fix this so that probing all luns works correctly with
> > > ide-scsi?
> >
> > Ask the ide-scsi maintainer I guess.
>
> multi-lun IDE devices do exist, so in that sense the driver is correct
> in allowing multi-lun probes. It is just that most IDE devices ignore
> the LUN field and respond to each LUN. This is usually just a minor
> inconvinience, as the device is detected eight times.

I've actually never seen one or the changer I had didn't support it (it was
an nec 6x 4disc)

> Over the times, there have been reports of actual kernel oopes which seemed
> related to multi-lun support on the surface, and I repeatedly got patches
> which disabled multi-lun probing, even though the multi-lun support iself
> can't be the cause of the problem; it just allows the SCSI subsystem
> to send packet commands with a lun field different than zero. Any kernel
> crash has its reasons in another (real) bug.
>
> That said, there might be a way to support multi-lun devices and still
> detect normal devices just once. multi-lun devices are supposed to have
> a "max lun" field in response to the ATAPI IDENTIFY command, and perhaps
> multi-lun devices return x > 0 in those fields, while other return 0
> (or perhaps 7?).
>
> If anybody is interested in testing this, add something like:
>
> if (drive->id)
> printk("%s: last-lun: %d\n", drive->name,
> drive->id->word126 & 0x7);
>
> to idescsi_setup in drivers/scsi/ide-scsi.c. To know if we can use this
> field, we need test results both from users of multi-lun IDE devices
> (such as PD-CD drives), and from users of single-lun IDE devices.

If you tell me what line, i'll add it into 2.2.13pre18 and try it on a
machien I have at work.

> > > what if I have a cdchanger on a scsi card and I use ide-scsi with another
> > > cdrom?
> >
> > Youre screwed for now 8)
> >
> > -Dan
>
> No, having a cd-changer on another SCSI card should not be related to
> ide-scsi. Enabling multi-lun should add support for both.

Actually, I'll agree with him. load module for scsi card before ide-scsi.
found a 5disc changer on the scsi card, ok, scd[0-4] is that changer. Load
ide-scsi and then see 6-8 devices for the same ide cdrom. This is what he
meant by screwed for now.

-- 
 Lab tests show that use of micro$oft causes cancer in lab animals

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