Subject: Re: ATA/ATAPI kernel redesign
To: <>
From: David Laight <david@l8s.co.uk>
List: tech-kern
Date: 02/25/2002 19:56:26
> > A certain box - that will run sparc solaris, and might get into the
> > 'aftermarket' soon - has 4 PCI IDE controllers (8 channels) that
> > control a maximum of 4 disks (1).  Doing the 30s timeout in series
> > takes far too long....
> 
> Yes, and you can easily have 6 pciide controllers in a PC (2 on motherboard
> and 4 add-on), I have 5 at home in my text box. This is why I added shortcuts
> for some patterns, which are not in the specs at all but seems to work fine
> by experience.

Ah - but you could cable up lots of drives on your home system...
The one I'm talking about can only ever access the 4 disks
(if you want a CDROM you have to use an external SCSI one....)

IIRC a big problem is detecting slave only configurations.
The 30sec timeout is actually waiting for the master device
to determine whether a slave is present.  I suspect 30 secs
is allowing time for the slave to access its media in
order to find out whether it is there or not.

	David

-- 
David Laight: david@l8s.co.uk