Subject: Re: siop(4) and tagged queuing
To: Matthew Jacob <>
From: Manuel Bouyer <>
List: current-users
Date: 10/23/2000 19:41:20
On Mon, Oct 23, 2000 at 10:30:46AM -0700, Matthew Jacob wrote:
> SPI allows for 256 tags. Manage the limit unless it desperately costs you.

Well, it does. The script RAM is of limited size (4 or 8K) and I'd prefer
to keep the tag switches in the RAM (fetching the instructions through the
PCI bus can add significant delays when there's several busy HBAs on the same
PCI bus).
I'll think more about this for esiop (another driver which uses features
present only in newer chips).

> Your typical disk drive will manage at least 64 tags these days w/o sending
> back QFULL.

Ok, I'll keep this in mind.

Manuel Bouyer, LIP6, Universite Paris VI.