Date: Mon, 01 Jun 1998 12:17:04 +0200 From: "Jose M. Alcaide" <jose@we.lc.ehu.es> To: Gary Palmer <gpalmer@FreeBSD.ORG> Cc: freebsd-scsi@FreeBSD.ORG, gibbs@narnia.plutotech.com, borjam@we.lc.ehu.es Subject: Re: AHC: "cheksum error" reading SEEPROM with Iwill PIILS mb Message-ID: <35727FA0.E394F452@we.lc.ehu.es> References: <25690.896579042@gjp.erols.com>
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Gary Palmer wrote:
>
> "Jose M. Alcaide" wrote in message ID
> <356D9CF8.1E7667F5@we.lc.ehu.es>:
> > When the AHC driver tries to read the 7880's SEEPROM, the operation
> > fails with a "cheksum error". I'm afraid that the 7880 chip on my
> > PIILS motherboard is different (perhaps another version?): for
> > example, I cannot choose the termination type using the Adaptec
> > SCSI BIOS ("High ON/Low ON", "High ON/Low Off"...); instead, I can
> > only select "Enable" or "Disable". However, the "cheksum error"
> > trying to read the 7880's SEEPROM does not prevent the AHC driver
> > from working properly. Until now, I can use both the SCSI disk and
> > CD-ROM without any problem.
>
> The SEEPROM (Serial EEPROM) is something that Adaptec PCI cards use
> to store their configuration on. However, on-board controllers don't
> have an SEEPROM as they normally have the settings in the BIOS. Hence,
> the SEEPROM checksum fails because there isn't one :)
>
> The AHC driver has sensible enough defaults that it should Just Work (TM)
> when an SEEPROM is not found.
>
Mmmm... I have two Dell Poweredges with embedded 7880s, and they
_have_ SEEPROM; there is no "checksum error" on these machines.
Well, perhaps the Iwill PIILS mb has no SEEPROM, but... perhaps
it has one, but there is _indeed_ a checksum error because of
some difference in the format of the data.
I have examined carefully sys/pci/aic7870.c. The format of the
SEEPROM registers is defined in this file. It can be seen
(lines 154-155, version 1.41.2.8) that there are two bits in
the "Host Adapter Control Bits", labeled CFSTERM and CFWSTERM,
which inform about the low/high byte termination of the SCSI bus.
I insist that the SCSISelect utility of my PIILS motherboard
only permits the "Enable" and "Disable" states for the SCSI
host adapter termination; instead, when using SCSISelect on
the Dell Poweredges, I can choose all combinations of high/low
byte termination.
I have just edited sys/pci/aic7870.c, adding to it code for
printing the contents of scarray[], which supposedly stores
the contents of the SEEPROM after calling read_seeprom().
This is the result:
808e 808e 808e 808e 862d bfc0 bfff bfff bfff bfff bfff bfff bfff
bfff bfff bfff bfff bfff bfff bfff bfff bfff bfff bfff bfff bfff
bfff bfff bfff bfff bfff
Strange, isn't it?
Also, although I have a IBM DDRS 34560W HD, which support Ultra
speed, the AHC driver reports that it's using 10 MHz transfers with
this drive. The reason is that it uses the BIOS defaults, which
(I don't know why) have the Ultra speed disabled. I made another
slight modification to aic7870.c, setting ultra_enb=1, and now
the AHC driver uses 20 MHz transfers with my HD.
In summary, I don't know if the Iwill PIILS mb has SEEPROM or not.
If it has one, the AHC driver does not read it correctly. If the mb
hasn't a SEEPROM, then the Ultra SCSI speed is not enabled in
the BIOS defaults used by the driver. However, I enabled this
feature using the SCSISelect utility.
Thanks for your patience,
-- JM
-----------------------------------------------------------------------
Jose M. Alcaide | mailto:jose@we.lc.ehu.es
Universidad del Pais Vasco | http://www.we.lc.ehu.es/~jose
Dpto. de Electricidad y Electronica |
Facultad de Ciencias - Campus de Lejona | Tel.: +34-944647700 x2624
48940 Lejona (Vizcaya) - SPAIN | Fax: +34-944858139
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