Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 30 Jun 2000 09:38:03 +0200
From:      Andre Albsmeier <andre.albsmeier@mchp.siemens.de>
To:        Andre Albsmeier <andre@internal.FreeBSD.ORG>, SUCCESS@FreeBSD.ORG, FAILURE@curry.mchp.siemens.de, DELAY@curry.mchp.siemens.de
Cc:        "Kenneth D. Merry" <ken@kdm.org>, Andre Albsmeier <andre.albsmeier@mchp.siemens.de>, freebsd-scsi@freebsd.org, gibbs@freebsd.org
Subject:   Re: Curiuos Problem with CAM and a 2940U2W with several devices
Message-ID:  <20000630093803.A1035@curry.mchp.siemens.de>
In-Reply-To: <20000630082310.A8783@curry.mchp.siemens.de>; from andre@curry.mchp.siemens.de on Fri, Jun 30, 2000 at 08:23:10AM %2B0200
References:  <20000629080730.A66792@curry.mchp.siemens.de> <20000629125305.A61135@panzer.kdm.org> <20000630082310.A8783@curry.mchp.siemens.de>

next in thread | previous in thread | raw e-mail | index | archive | help
[ Now CC'ing Justin myself ]

On Fri, 30-Jun-2000 at 08:23:10 +0200, Andre Albsmeier wrote:
>
> ...
>   
> Today in the morning I have investigated this further, it is really
> curious. I will sum up all what I have done to make it easier to
> understand. I will just desribe what was attached to the 2940U2W
> and what happend. The connectors are referred to as follows:
> 
> LVD-ext: external accessible LVD connector of the 2940U2W
> LVD-int: the internal LVD connector
> 50p-int: the SE 50 pin connector
> 68p-int: the SE 68 pin connector 
> 
> LVD-Trm and SE-Trm will show the settings of the two corresponding
> entries in the 2940U2W BIOS.
> If any cable was attached to any connector, it was terminated properly
> with an appropriate, active terminator.
> 
> The 2940U2W was flashed with BIOS 2.57.2.
> 
> The word "Errors" means errors in the dmesg already during the
> boot phase when booting with 'boot -s'. These errors are always
> as being written in my previous mail.
> 

Quoting myself but there are interesting news: I can easily
reproduce the problem on a different machine with another
2940U2W:

da0: <QUANTUM XP32275W LYK8> Fixed Direct Access SCSI-2 device
da1: <QUANTUM XP32275W LYK8> Fixed Direct Access SCSI-2 device
da2: <QUANTUM XP34550W LYK8> Fixed Direct Access SCSI-2 device
da3: <QUANTUM XP34550W LYK8> Fixed Direct Access SCSI-2 device
da4: <FUJITSU MAE3182LP 5210> Fixed Direct Access SCSI-2 device
cd0: <TEAC CD-ROM CD-532S 1.0A> Removable CD-ROM SCSI-2 device

This is the configuration:
 
  LVD-ext:  noting
  LVD-int:  MAE3182LP LVD
  LVD-Trm:  enable

  50p-int:  CD-532S
  68p-int:  all Quantum drives from above
  SE-Trm :  low/off high/on

  Result :  errors (someone reset channel A, ...)


But as soon as I remove one of the 3 connected cables (no matter
if it is LVD-int, 50p-int or 68p-int) and adjust the termination
settings properly, it works.

I already wanted to send this email when I got another idea:

  LVD-ext:  nothing
  LVD-int:  only a terminated cable
  LVD-Trm:  enable

  50p-int:  only a terminated cable
  68p-int:  all Quantum drives from above
  SE-Trm :  low/off high/on

  Result :  errors (someone reset channel A, ...), as expected


And here comes the funny thing:

  LVD-ext:  nothing
  LVD-int:  only a terminated cable BUT TERMINATED WITH AN SE TERMINATOR
  LVD-Trm:  enable

  50p-int:  only a terminated cable
  68p-int:  all Quantum drives from above
  SE-Trm :  low/off high/on

  Result :  works


As a result we can say: It fails if both of the SE connectors are in use
and an LVD path is connected to the LVD-int connector. When using an
SE path on the LVD-int connector it works.

The funny thing is that Winblows95 has no problems with all of the
above configurations.

So I slowly might come to the point that there is indeed a problem
with the way how FreeBSD uses the 2940U2W. First, I thought it would
be one of the devices but as we can see, this isn't the case.

Since I have now reproduced the problem on my own machine, I can
easily test any suggestions in order to fix this.

Thanks,

	-Andre


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-scsi" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20000630093803.A1035>