Adaptec AIC7902 Ultra320 Problems

Justin T. Gibbs gibbs at
Tue Jul 22 09:44:35 PDT 2003

> I have a Supermicro SuperServer 6013P-8, with:
> ahd0: <Adaptec AIC7902 Ultra320 SCSI adapter> port
> 0x4000-0x40ff,0x4400-0x44ff mem 0xfc300000-0xfc301fff irq 5 at device 2.0 on
> pci3
> aic7902: Ultra320 Wide Channel A, SCSI Id=7, PCI-X 101-133Mhz, 512 SCBs
> ahd1: <Adaptec AIC7902 Ultra320 SCSI adapter> port
> 0x4800-0x48ff,0x4c00-0x4cff mem 0xfc302000-0xfc303fff irq 5 at device 2.1 on
> pci3
> aic7902: Ultra320 Wide Channel B, SCSI Id=7, PCI-X 101-133Mhz, 512 SCBs
> Trying to install 5.1-CURRENT-20030709-JPSNAP or 4.8-STABLE on the
> box gives a timeout error that will hang the disk in a state that
> resetting the machine does not clear, and only power cycling will
> clear. Ive replaced the disks with no change, but installed and
> ran Redhat 7.3 on the box with no timeouts or errors.

The problem you are encountering looks to be a drive firmware issue
exposed when the drive is running at high queue depths.  The linux
driver limites the tag depth to 32 by default.  The FreeBSD driver
does not throttle in this way.  It seems that we just overwhelm the
drive with commands and it just stops doing anything on the bus.  According
to the timeout trace, the target just stopped sending packets while
still sitting on the bus.

I have not tested this particular drive, so I do not know if update
firmware is available for it.  You might try running in non-packetized
mode by toggling this option via SCSI-Select.  You previous test of
running at "160" just reduced the clock rate, but still allowed the use
of the newer, faster, packetized format.


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