>Number:         13365
>Category:       kern
>Synopsis:       writing to floppy disk while accessing siop scsi can lock up machine
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jul 03 12:31:00 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     Bernd Sieker
>Release:        NetBSD 1.5.1
>Organization:
Bernd Sieker

Of course it runs NetBSD
>Environment:
System: NetBSD boa.home.loc 1.5.1 NetBSD 1.5.1 (BOA) #0: Wed Jun 20 13:23:10 CEST 2001 bernd@boa.home.loc:/usr/local/src/sys/arch/i386/compile/BOA i386

PC, Asus P2B-B board, Celeron-366, 256MB RAM, ATI Rage Pro graphics (AGP),
Tekram DC390F UW-SCSI (siop0 at pci0 dev 9 function 0: Symbios Logic 53c875 (ultra-wide scsi)),
DECChip 10/100 Ethernet (de0: SMC 9332DST 21140 [10-100Mb/s] pass 1.2),
Hoontech PCI sound card (yds0: SigmaTel STAC9708 codec; 18 bit DAC, 18 bit ADC, Rockwell 3D)
2 IBM DCAS 4GB, 1 IBM DNES 18GB disks, 1 Pioneer DVD DVD-ROM DVD-303,
1 Teac CD-R CD-R58S.
Standard Floppy Disk (fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2,
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec)
No IDE/ATA devices.

>Description:
Sometimes, when trying to write something from scsi hard disk to floppy
disk, the system totally locks up, nothing happens at all, the scsi LED
stays lit, no keyboard input is possible, no mouse input, the screen is
frozen, the machine is not pingable, no panic, no core dump, just dead.

This started happening as soon as I moved the /home/ to a scsi disk, it
happened never before when it was on an IDE disk. This is why I suspect
a problem with the siop scsi driver.

Sometime using mtools to write to floppy works, as does mounting the
disk and writing single files to it. Using dd almost always fails.
Writing larger or more files with mtools or to a mounted floppy disk
usually fails, too.

I'm sorry I cannot provide any debugger output, since I cannot _enter_
the kernel debugger.

>How-To-Repeat:
On an affected machine (I have no idea what exactly is required to make
the problem appear) try (e. g.) to dd a disk image file to a floppy
disk.

>Fix:
Not known.

>Release-Note:
>Audit-Trail:
>Unformatted: