Date: Mon, 19 Nov 2001 15:08:48 -0700 From: "Justin T. Gibbs" <gibbs@scsiguy.com> To: "Jose M. Alcaide" <jose@we.lc.ehu.es> Cc: scsi@FreeBSD.ORG Subject: Re: weird problems with on-board Adaptec 7880 Message-ID: <200111192208.fAJM8mY88365@aslan.scsiguy.com> In-Reply-To: Your message of "Mon, 19 Nov 2001 19:13:22 %2B0100." <20011119191322.F337@v-ger.we.lc.ehu.es>
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>> Ensure the DLT does not have a jumper or dip switch for internal >> termination. > >But when I attach the DLT to the external connector of an Adaptec 2940U >controller, it works just fine. OTOH, I also tried to *only* attach the >internal Ultra-SCSI CD-ROM and CD-RW devices (terminating the bus using >the jumper of the device at the end of the chain), and I also get low sync >rates (5 MHz, 5.813 MHz). If I attach these devices to the Adaptec 2940U >(using the same cable) they work fine at 20 MHz sync rates. I don't think the syncrate problem is at all related to why the bus does not work. The bus doesn't work because termination *on the controller* is not set correctly. Your test with the 2940U can't detect all termination issues. >> It may be useful. > >ahc2: <Adaptec aic7880 Ultra SCSI adapter> port 0xe400-0xe4ff mem 0xe5903000-0 >xe5903fff irq 14 at device 20.0 on pci0 > >Serial EEPROM: > 0xb0ee 0xb0ee 0xb0ee 0xb0ee 0x8629 0xbfff 0xbfff 0xbfff > 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff > 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff > 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff 0xbfff > >Serial EEPROM: > 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb > 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb 0xc3bb > 0x18a6 0x1c5e 0x2807 0x10 0xffff 0xffff 0xffff 0xffff > 0xffff 0xffff 0xffff 0xffff 0xffff 0xffff 0xffff 0x98c0 The dump is only useful with an understanding of the corresponding SCSI Select settings. Please go into SCSI select and set the transfer rate from fastest to slowest across the SCSI IDs. This will provide a better understanding of how this BIOS is setting the SEEPROM. Also include the SCSI BIOS version for this controller. >> >**NOTE:** the SCSI-select utility offers only two choices for bus >> >termination: "High ON/Low Auto" or "High OFF/Low OFF". If I attach devices >> >to both SCSI onboard connectors (wide and narrow), the "boot -v" messages >> >keep saying "Low byte termination enabled". Is that the expected behavior? >> >> Depends on the motherboard. Many of these systems actually control >> the termination via a MB BIOS control. The SCSI Select controls were >> never disabled when the SCSI BIOS was compiled. I believe that this may >> be the cause of your bus instability. > >The motherboard has a jumper labeled "SCSI Autoterm ON", and I tried to >remove it to no avail. The motherboard manual does not tell anything about >this jumper, however. Well, the serial eeprom indicates that termination is hardcoded to on for both the high and low byte. Can you provide an SEEPROM dump for each different termination setting available? Please label them with what options are enabled. -- Justin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-scsi" in the body of the message
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