[5730] in linux-scsi channel archive
Re: Adaptec 2940UW controller driver for Linux
daemon@ATHENA.MIT.EDU (Henrik Johansson)
Thu Jan 28 05:40:22 1999
Date: Thu, 28 Jan 1999 11:40:39 +0100
From: Henrik Johansson <henrik@lcdata.se>
To: "Allison, Bob" <BOB.allison@qwest.com>
Cc: "'doctor@fruitbat.org'" <doctor@fruitbat.org>,
david.c.hoos.sr@ada95.com, mhuff@colltech.com,
linux-scsi@vger.rutgers.edu
Hi,
Have You triple-checked the terminations? The 2940U2W board is VERY
sensitive to this. Also worth checking the settings on the host adapter in BIOS.
(No wide negotiation with narrow devices and so forth.)
// Henrik J.
Allison, Bob wrote:
> Well, maybe you can tell me what I did wrong.
>
> I pulled out the 2940UW and put the 2940U2W in its place, plugging the
> 50-pin ribbon into the U2W exactly as it was in the UW.
>
> When I powered up the machine, the U2W saw no devices (at the BIOS listing,
> had a hard time booting from /dev/sda2).
>
> I swapped the boards back and everything was fine (both disks, the CD, and
> the tape were back).
>
> -----Original Message-----
> From: doctor@fruitbat.org [mailto:doctor@fruitbat.org]
> Sent: Wednesday, January 27, 1999 3:06 PM
> To: BOB.allison@qwest.com
> Cc: david.c.hoos.sr@ada95.com; mhuff@colltech.com;
> linux-scsi@vger.rutgers.edu
> Subject: Re: Adaptec 2940UW controller driver for Linux
>
> Allison, Bob said ...
> >
> > AFAIK, the 274x/284x/294x driver in Linux supports all of the 294x family,
> > including the 2940U2W (at least, it was recognized on my system).
> >
> > The 2940U2W uses UltraSCSI signal levels (LVD=Low Voltage Differential).
> > Although the documentation indicates that it can drive single-ended as
> well
> > as differential devices, I found that it would not drive my older SCSI-2
> > drives. This is because they require a higher signal voltage.
>
> Untrue. The controller has a fall back mode in which it will switch to
> SCSI-II signal levels to support non-LVD devices on the U2 bus. However,
> mixing LVD and non-LVD on the same bus will reduce the through-put to
> SCSI-II levels. I've a mix of devices on the LVD bus and this is the
> results I get. Perhaps you didn't have proper termination?
>
> > Unless you have LVD devices, you better stick to the 2940UW for SE devices
> > and 2944UW for FWD devices.
>
> Na. The 2940U2W does quite well for either.
>
> --
> Peter A. Castro (doctor@fruitbat.org) or (pcastro@us.oracle.com)
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.rutgers.edu
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.rutgers.edu
-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.rutgers.edu
