Ongoing U320 AIC7902 Seagate ST318453LW issues, SCB timed out

[Don Bowman]

From: Justin T. Gibbs [mailto:gibbs at scsiguy.com]

> > On some systems I am sometimes getting this error pop out.
> > It seems to track the system for some reason. This is
> > not a bad cable, signals look good on oscope.
> > 
> > Drive is: SEAGATE ST318453LW, FW 0005
> 
> You seem to have found another way to trip up the Seagate drives.
> According to the controller, there are 13 commands that are 
> outstanding
> on the drive that have not been completed within the timeout period.
> The bus is idle and so is the controller.
> 
> The SCB count in this dump is 64.  Are you not throttling the number
> of commands to 32 for these devices?  If so, the SCB count should not
> be higher than 32 for a single drive configuration.  I have 
> seen behavior
> similar to what you are experiencing with tag depths greater than 32.

I'm continuing to test without the throttle. I'm @ a loss for why
it tracks some systems and not others.

There doesn't seem to be a reliable way to drop the number of
tags since the system may not always come up. I don't think
there's an option in the kernel to do so.

--don