On Mon, Jun 25, 2007 at 02:47:08PM -0400, Greg Troxel wrote:
> 
> My system is NetBSD/i386 4.0_BETA from around May 1.
> 
> I have been using a DDS3 on a 2940A for a very long time with absolutely
> no problems (well, other than occasional media errors and that the tapes
> are too small).
> 
> I have a shiny new Quantum LTO-2 tape drive, with a wide connector
> (68-pin micro).  I got an Adaptec 29160N "Ultra 160" controller, with an
> external 50-pin micro connector, because the 29160 was 64-bit PCI and
> not listed as supported in NetBSD.
> 
> I have a 50-pin to 68-pin cable connecting the controller to the tape
> drive.  For reasons I don't understand the controller negotiates 16-bit
> transfers with the tape drive.
> 
> ahc2 at pci1 dev 2 function 0: Adaptec 29160N Ultra160 SCSI adapter
> ahc2: interrupting at ioapic0 pin 18 (irq 5)
> ahc2: aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs
> scsibus1 at ahc2: 16 targets, 8 luns per target
> 
> st0 at scsibus1 target 5 lun 0: <CERTANCE, ULTRIUM 2, 1914> tape removable
> st0: drive empty
> st0: sync (50.00ns offset 127), 16-bit (40.000MB/s) transfers
> ahc2:parity error detected in Data-in phase. SEQADDR(0x1ae) SCSIRATE(0x95)
> ahc2:parity error detected in Data-in phase. SEQADDR(0x1ae) SCSIRATE(0x95)
> ahc2:parity error detected in Data-in phase. SEQADDR(0x1ae) SCSIRATE(0x95)
> ahc2:parity error detected in Data-in phase. SEQADDR(0x1ae) SCSIRATE(0x95)
> ahc2:parity error detected in Data-in phase. SEQADDR(0x1ae) SCSIRATE(0x95)
> ahc2:parity error detected in Data-in phase. SEQADDR(0x1ae) SCSIRATE(0x95)
> 
> 
> I then hooked up the drive to the old controller, and it seems to work,
> but it stops/starts which isn't good.  I don't understand why this isn't
> going for 20 MB/s transfers.

Well, you have a 16bit-capable adapter and 16bit-capable target, so they
negotiate 16 bits. They have to way knowing that the cable is only 8 bits
(other than the parity error when trying to use the 16-bit path).

> 
> I will try the SCSI bios to try to set things to the right rates.  Does

This may help

> anyone have any clues?  Does anyone know if the 29160 (no N) works?

Yes, it does.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--