Subject: Re: dynamic configuration (was Re: PR#4094)
To: None <thorpej@zembu.com>
From: Nathan J. Williams <nathanw@MIT.EDU>
List: tech-kern
Date: 08/28/2000 11:18:28
<thorpej@zembu.com> (Jason R Thorpe) writes:

> On Mon, Aug 28, 2000 at 12:06:39AM -0700, Todd Whitesel wrote:
> 
>  > > You want better boot performance? Get rid of mandatory SCSI bus
>  > > settle time that is now currently enforced to default to 2
>  > > seconds per scsi bus (requires fixing HBA drivers to force
>  > > negotiations to narrow/async as they should > > > > That 2
>  > > seconds per bus is a great improvement over what it _used_ to
>  > > be.
> 
> Actually, it always waited the 2 seconds.  I merely added the
> notification that it was doing so.

Since it seems that the goal is to wait two seconds between SCSI bus
attachment and SCSI bus probe, it seems that the best thing to do
would be to grab the time when the bus is attached and see if two
seconds have passed before probing the bus. I suppose that the lack of
timer interrupts during most of autoconfig makes this hairy, though.

But in the case of booting a system where several SCSI busses are
detected, only one two-second delay should be needed. A little static
variable in scsibus_config_interrupts() should be able to handle that.

        - Nathan