Re: AIC7XXXX bug in 2.0.34

Richard B. Johnson (
Fri, 5 Jun 1998 14:26:04 -0400 (EDT)

On Fri, 5 Jun 1998, Doug Paul wrote:

> There appears to be an intermittant bug in the boot sequence for
> the AIC7XXX driver in 2.0.34.

[Symptoms snipped]
Timeouts upon bootup are almost always caused by:
(1) Disk drives drive(s) dragging power supply voltage down as they
spin up. Reboots will work without errors.
(2) Improper termination of cables.
(3) Too many devices on the SCSI bus.

This Adaptec controller will not reliably drive more than 4 devices even
though it is supposed to do so. This is why I went to BusLogic. The
bus interface chip has a relatively high output impedance.

Make very sure that the termination resistor(s) are powered! It is easy
to blow the fuse on the controller board by connecting a SCSI cable
backwards. Just enable "termpwr", but NOT termination, on all your
SCSI devices. This will make sure that the terminator(s) are powered
even if the fuse on the controller is blown.

Dick Johnson
Penguin : Linux version 2.1.103 on an i586 machine (66.15 BogoMips).
Warning : It's hard to remain at the trailing edge of technology.

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