From: nbladt@autelca.ascom.ch (Norbert Bladt)
Subject: Re: Adaptec 1740 problem.
Organization: Ascom Autelca AG, Guemligen, Switzerland
Distribution: comp
Date: Tue, 15 Sep 1992 07:33:14 GMT

eric@tantalus.dell.com (Eric Youngdale) writes:


>	I am trying to track down a SCSI problem that is coming up with
>linux.   The person who reported the problem is using an Adaptec AHA1740
>and he is saying that the controller will read the wrong disk block every
>so often.  

[ text describing the real problem deleted - NB. ]

>Currently my best guess is that the problem is one of two things:

>	1) We are treating the 1740 the same as a 1540 insofar as the hard disk
>usage is concerned (i.e. identical code).  The kernel uses one outgoing
>ccb/mailbox, and one incoming ccb/mailbox, and it waits for one command to
>complete (and interrupt the system) before it queues another command.  I do not
>believe that any error conditions are being reported, although the kernel is
>set up to retry the read for certain types of errors, and if this were
>happening we would not be aware of it.  The automatic request sense is enabled.
>Is there some difference between the 1740 and 1540 that we need to take into
>account???
It might be :-)
I did boot 386BSD (with the new drivers) on an EISA system with 1742A and it
detects my harddisk. The 1742A is running in STANDARD, i.e. 1542B mode.
The same code is used for both controllers.

>	2) The 1740 is at bios level 1.34.  Could there be a firmware bug?
>(Since linux is a virtual mode OS, we do not use the bios for anything except
>for boot-time initialization.  The bios level could suggest something about the
>firmware level that is on the board).
I have the same bios version on my board (1742A). One answer for my request
for help was saying that there is a bug in the 1740 BIOS which was not fixed
till spring this year, at least. If you are using CCB opcodes 3 and 4
you might be out of luck because of this bug.

>	If anyone has any constructive suggestions as to what the
>problem could be I would be intersted in hearing them.  I have
>enclosed his configuration at the end of this mail message
Now, I don't know what the real difference between the original
SCSI driver in 386BSD 0.1 and the new drivers are. That means I don't know
what feature did cure the problem of 386BSD in not finding my harddisk.
What I know for sure is that in the new driver the opcodes 3 and 4 or not
used compared to the old driver where they were used !
On the other hand it could just be a timing problem (DMA 5 MB/s vs. 33 MB/s).
I don't know the exact reasons why the new driver works.

>	Thanks in advance.  Please reply to eric@tantalus.nrl.navy.mil
Hope this helps, at least, a little !

>Central stuff:
>    Tower case w/8 drive bays and 250-watt power supply
same for me.
>    Intel 32-bit 80486 CPU @33MHz
same for me.
>    Micronics EISA motherboard w/8 EISA slots and 64KB cache RAM standard
no-name clone EISA, 8 slots, 256k Cache.
>    Support for Weitek 4167-33 math co-processor (no chip yet)
same
>    Phoenix 80486/EISA ROM BIOS PLUS Version 1.01.22-2
Modular BIOS (Copyright Award, 1990,91)
>    16MB RAM, @70ns?
same for me.
>    2 serial ports, 1 parallel port
same for me.

>Peripherals:
>    Adaptec AHA-1740 SCSI-2 controller (BIOS v1.34)
same for me (except 1742A, i.e. 1740 with floppy controller for two drives).
>    Maxtor PO-12S 1.2GB SCSI-2 hard drive
520 MB Fujitsu drive.
>    5.25" (1.2MB) internal floppy
same.
>    3.5" (1.44MB) internal floppy
same.
>    Colorado Jumbo 250 tape drive (thru floppy interface, I think)
No streamer, yet. Will be Archive 150 MB, cheap, standard.

>Hard Drive Partitioning:
>    64MB DOS, 807MB DOS extended, 62MB Linux, 64MB Linux (first
>    two done by DOS FDISK, latter two done by hand using DOS DEBUG)
Totally different, but about 100MB for DOS, rest intended for 386BSD.

>Wetware Interface:
>    Sigma Designs L-View 1664x1200 120dpi 4-gray-scale monitor & card
doesn't matter.
>    Northgate Computer Systems' OmniKey/101 (modified so CTRL to left of
>        "A", CAPS LOCK left of SPC, etc)
doesn't matter.
>    Standard Technologies Mouse (switchable Microsoft/Mouse system)
Genius Mouse (cheap Mouse Systems Mouse clone)
>    Howtek Scanmaster (not hooked up yet)
no.
-- 
Norbert Bladt, Ascom Autelca AG, Worbstr. 201, CH-3073 Guemligen, Switzerland
Phone: +41 31 999 65 52			FAX: +41 31 999 65 44
Mail: nbladt@autelca.ascom.ch   UUCP: ..!uunet!mcsun!chsun!hslrswi!aut!nbladt
Newsgroups: comp.periphs.scsi