Messages in this thread | | | Date | Tue, 19 Oct 1999 08:20:07 +0200 (IST) | From | Gadi Oxman <> | Subject | Re: Oops with 2.2.13pre17 and ide-scsi |
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On Mon, 18 Oct 1999, Dan Hollis wrote:
> On Mon, 18 Oct 1999, Wakko Warner wrote: > > > 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.
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.
> > 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.
Gadi
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