Re: Fdomain + CD ROM access -> kernel panic

Dean Martin Townsley (townsley@physics.ucsb.edu)
Sat, 04 Sep 1999 17:30:42 -0700


> > Kernel panic: scsi: <fdomain> fdomain_16x0_queue() NOT REENTRANT!
> > In swapper task - not syncing
> >
> > Using either the CD or the SCSI without accessing the other works fine. I've
> > tried all kinds of stuff (moving cards around, changing BIOS settings etc etc)
> > to no avail. Any suggestions on a way to figure out what is going on would
> > be much appreciated.

> It seems to be a bug in the SCSI layer handling code. I can duplicate this
> in some other cases where the scsi layer queues commands when the driver
> has explicitly said not to do so.

> A hack that kind of seems to work is to edit the .h file for the driver and
> turn off queueing support.

Thanks for the reply! I've got some weirdness though. I thought I had tried
this about a week ago (setting can_queue to 0 in fdomain.h) but just to make
sure I tried again. Now if I set can_queue to 0 the kernel doesn't even make
it through the boot sequence, it freezes just after detecting the SCSI
adapter, i.e. right after:

...
Floppy drive(s): fd0 is 1.44M
FDC 0 is a post-1991 82077
scsi0: <fdomain> No BIOS; using scsi id 7
scsi0: <fdomain> TMC-36C70 (PCI bus) chip at 0xec00 irq 11
scsi0 : Future Domain 16-bit SCSI Driver Version 5.50
scsi : 1 host

and I mean freeze, no scrollback even. It should detect the drive at this
point but doesn't.
I'm really clueless now. I might try to play with some queue logging to
see if I can get it to tell me any more.
Thanks again for the reply,
-Dean Townsley
<townsley@physics.ucsb.edu>

Note: the irq above is different from my previous post because I hopped the
card to another slot to see if that would get it to boot, it didn't.

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