On Wed, Mar 15, 2000 at 12:25:08AM -0500, alexis@panix.com wrote:
> Frank wrote:
> > I just checked in a new version of the ahc driver (Adaptec SCSI), based
> > on the FreeBSD driver by Justin Gibbs.
> > 
> > [...]
> > Note that the option that the old driver had to enable tagged queueing
> > (AHC_TAGENABLE) isn't there yet. I will put it in later this week,
> > I think. I don't think many people used this option, as it used
> > to have some problems.
> 
> But that's why it wasn't used- had the driver worked, everyone with
> halfway-modern drives would turn it on. The cards themselves, as far as
> I know, work properly. If this feature works properly, is there any
> reason not to use it? Do you anticipate it working properly in the new
> driver?

It is possible that a bug Thor and I discovered in every SCSI driver 
that used a software queue was the cause of tagged queueing problems.

Essentially, the moment the card ran out of SCBs it was destined to panic
by calling tsleep() from an interrupt context.

I really should try enabling tagged queueing again.

-- 
Bill Squier (groo@cs.stevens-tech.edu)
http://www.cs.stevens-tech.edu/~groo
Ph: (201)216-5486   Fax: (201)216-8249