Date: Fri, 8 Sep 95 16:03:56 +0100 From: Jean-Marc Zucconi <jmz@cabri.obs-besancon.fr> To: se@zpr.uni-koeln.de Cc: current@freebsd.org Subject: Re: Another NCR problem Message-ID: <9509081503.AA04139@cabri.obs-besancon.fr> In-Reply-To: <199509080858.AA28390@Sysiphos> (se@zpr.uni-koeln.de)
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>>>>> Stefan Esser writes:
> } The machine is a P90 (Asus P55TP4XE Mainboard, Asus SC-200 scsi
> } controler, Diamond 968 Vram video)
> Is the Asus SC-200 at one end of the SCSI cable, and if Yes: Does
> it include an active terminator ? (The NCR8150S board does, but
> many other 53c810 based boards don't ...)
The SC-200 is at the end of the internal cable, external devices are
connected to the external connector. The board has an active
terminator, but (following the installation sheet) it is disabled
(there is a jumper for this) since I have both external and internal
devices.
> } This happens some time after I start the system, and when there is
> } some activity on the scsi bus: I was doing a backup of the
> } disk(lun#4), but I already wrote 4 tapes w/o any problem.
> I see.
> } > Can you send a boot message log of the
> } > last version that did work ?
> }
> } No: this is a new machine (only up since sunday)
> } > } $ ncrcontrol -i
> } > } T:L Vendor Device Rev Speed Max Wide Tags
> } > } 0:0 MICROP 4110-09TBCU0322J HT01 10.0 10.0 8 3
> } > } 1:0 MICROP 2210-09MQ1001901 HQ30 10.0 10.0 8 4
> } > } 2:0 WANGTEK 5150ES SCSI ES41 B170 ? 5.0 ? -
> } > } 3:0 SONY CD-ROM CDU-8003A 1.9a 4.0 10.0 8 -
> } > } 4:0 QUANTUM LIGHTNING 540S 241E 10.0 10.0 8 -
> } > } 5:0 SONY CD-ROM CDU-55S 1.0f 3.6 10.0 8 -
> }
> } > Well, quite a number of devices ...
> } > How long is your SCSI bus cable, BTW ?
> }
> } targets 0,1,2 and 4 are internal (cable length ~ 60 cm - can't be
> } shortened!); the cdroms are external (length ~ 1.7m + 90cm). There
> } were no reads to the cdroms when the problem occured.
> Well, lets see, what the last public SCSI-2 draft says on this topic:
> # 5.2 Cable requirements
> #
> # The characteristic impedance of the cable should be no less than 90 ohms
> # and no greater than 140 ohms. The characteristic impedance of the cable
> # used when implementing the fast synchronous data transfer option is
> # defined in 5.2.3.
> [ ... ]
> # NOTES
> # 4 To minimize discontinuities and signal reflections, cables of different
> # impedances should not be used in the same bus. Implementations may require
> # trade-offs in shielding effectiveness, cable length, the number of loads,
> # transfer rates, and cost to achieve satisfactory system operation.
> [ ... ]
> # 5.2.1 Single-ended cable
> #
> # A 50-conductor flat cable or 25-signal twisted-pair cable shall be used
> # for the A cable. A 68-conductor flat cable or 34-signal twisted-pair
> # cable shall be used for the B cable if the wide SCSI option is
> # implemented. The maximum cumulative cable length shall be 6,0 m. If
> # twisted-pair cables are used, then twisted pairs in the cable shall be
> # wired to physically opposing contacts in the connector.
> #
> # A stub length of no more than 0,1 m is allowed off the mainline
> # interconnection within any connected equipment or from any connected
> # point.
> #
> # NOTE 7 Stub clustering should be avoided. Stubs should be spaced at least
> # 0,3 m apart.
> The interesting points are NOTE 4 and NOTE 7. If you mix internal
> and external cables, you most probably have different impedances.
> And with 4 devices on a 60 cm cable, you obviously can't have them
> at least 0.3 m apart ...
> The maximum length of 6 m does in general not work with transfer
> rates beyond 5MHz. I've had lots of problems with a workstation,
> that got an external disk and later an additional tape drive in
> distinct boxes. Adding the second box made the system crash within
> a few minutes of SCSI bus activity, independently of which device
> or set of devices was active.
> (I've seen FAST SCSI disk OEM manual list max. length vs. speed and
> in one case (a 1GB drive) I remember, the limit was 6 m at 2.2MHz,
> and 2 m at 5 Mhz ...)
> We switched to differential SCSI on all machines with any kind
> of external FAST devices for that reason, two years ago.
Now my kernel is compiled with SCSI_NCR_MAX_SYNC=0, so the cabling
quality should be less important.
The machine crashed again with this configuration. I then removed the
external devices and enabled the active terminators on the card. Still
crashing :-(((
Sep 8 15:22:24 qix /kernel: chip0 <Intel 82437 (Triton)> rev 1 on pci0:0
Sep 8 15:22:24 qix /kernel: chip1 <Intel 82371 (Triton)> rev 2 on pci0:7
Sep 8 15:22:24 qix /kernel: vga0 <VGA-compatible display device> rev 0 int a irq 12 on pci0:9
Sep 8 15:22:25 qix /kernel: ncr0 <ncr 53c810 scsi> rev 2 int a irq 11 on pci0:10
Sep 8 15:22:25 qix /kernel: ncr0: restart (scsi reset).
Sep 8 15:22:25 qix /kernel: ncr0 scanning for targets 0..6 (V2 pl22 95/07/07)
Sep 8 15:22:25 qix /kernel: (ncr0:0:0): "MICROP 4110-09TBCU0322J HT01" type 0 fixed SCSI 2
Sep 8 15:22:26 qix /kernel: sd0(ncr0:0:0): Direct-Access
Sep 8 15:22:26 qix /kernel: sd0(ncr0:0:0): asynchronous.
Sep 8 15:22:26 qix /kernel: 1002MB (2053880 512 byte sectors)
Sep 8 15:22:26 qix /kernel: (ncr0:1:0): "MICROP 2210-09MQ1001901 HQ30" type 0 fixed SCSI 2
Sep 8 15:22:26 qix /kernel: sd1(ncr0:1:0): Direct-Access
Sep 8 15:22:26 qix /kernel: sd1(ncr0:1:0): asynchronous.
Sep 8 15:22:26 qix /kernel: 1008MB (2065250 512 byte sectors)
Sep 8 15:22:26 qix /kernel: (ncr0:2:0): "WANGTEK 5150ES SCSI ES41 B170" type 1 removable SCSI 1
Sep 8 15:22:26 qix /kernel: st0(ncr0:2:0): Sequential-Access density code 0x10,
drive empty
Sep 8 15:22:26 qix /kernel: (ncr0:4:0): "QUANTUM LIGHTNING 540S 241E" type 0 fixed SCSI 2
Sep 8 15:22:26 qix /kernel: sd2(ncr0:4:0): Direct-Access
Sep 8 15:22:27 qix /kernel: sd2(ncr0:4:0): asynchronous.
Sep 8 15:22:27 qix /kernel: 525MB (1075649 512 byte sectors)
Sep 8 15:32:27 qix /kernel: ncr0: reset by timeout.
Sep 8 15:32:28 qix /kernel: sd0(ncr0:0:0): asynchronous.
Sep 8 15:32:40 qix /kernel: ncr0: reset by timeout.
Sep 8 15:32:52 qix /kernel: ncr0: reset by timeout.
Sep 8 15:32:52 qix /kernel: sd0(ncr0:0:0): asynchronous.
Sep 8 15:32:52 qix /kernel: sd0(ncr0:0:0): asynchronous.
Sep 8 15:32:53 qix /kernel: sd0(ncr0:0:0): COMMAND FAILED (4 88) @f0776c00.
Sep 8 15:37:44 qix /kernel: ncr0 targ 0?: ERROR (0:140) (a-2a-0) (e0/13) @ (4f8:1a000000).
Sep 8 15:37:45 qix /kernel: reg: da 10 80 13 47 e0 0 1f ff a 80 2a 0 20 a 0.
Sep 8 15:37:45 qix /kernel:
Sep 8 15:37:45 qix /kernel:
Sep 8 15:37:45 qix /kernel: Fatal trap 12: page fault while in kernel mode
Sep 8 15:37:45 qix /kernel: fault virtual address = 0x0
Sep 8 15:37:45 qix /kernel: fault code = supervisor read, page not present
Sep 8 15:37:45 qix /kernel: instruction pointer = 0x8:0xf017f50b
^^^^^^^^^^
ncr_exception()
Sep 8 15:37:46 qix /kernel: code segment = base 0x0, limit 0xfffff, type 0x1b
Sep 8 15:37:46 qix /kernel: = DPL 0, pres 1, def32 1, gran 1
Sep 8 15:37:46 qix /kernel: processor eflags = interrupt enabled, resume, IOPL = 0
Sep 8 15:37:46 qix /kernel: current process = Idle
Sep 8 15:37:47 qix /kernel: interrupt mask = bio
Sep 8 15:37:47 qix /kernel: panic: page fault
> } > Did you add devices lately ?
> }
> } No, but I can easily remove the cdroms.
> Yes, please do so!
They are now removed.
> } > Have you tried to boot a kernel built with:
> }
> } > options "SCSI_NCR_MAX_SYNC=0"
> }
> } No. I will do it now.
> Maybe a limit of 5MHz (SCSI_NCR_MAX_SYNC=5000) will suffice ...
I doubt :-)
> Regards, STefan
Jean-Marc
> --
> Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021
> Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160
> ==============================================================================
> http://www.zpr.uni-koeln.de/staff/esser/esser.html <se@ZPR.Uni-Koeln.DE>
_____________________________________________________________________________
Jean-Marc Zucconi Observatoire de Besancon F 25010 Besancon cedex
PGP Key: finger jmz@cabri.obs-besancon.fr
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