On Wed, Mar 07, 2007 at 10:37:54PM +0100, Manuel Bouyer wrote:
> 
> Could you try the attached patch against current ? This should fix the
> issue for the most common cases, and hopefully it won't break any working
> setups.
> 
> Manuel Bouyer <bouyer@antioche.eu.org>
>      NetBSD: 26 ans d'experience feront toujours la difference

> -	if (wd->sc_flags & WDF_LBA48 &&
> -	    (wd->sc_wdc_bio.blkno > LBA48_THRESHOLD ||
> -	    (wd->sc_quirks & WD_QUIRK_FORCE_LBA48) != 0))
> +	if (wd->sc_flags & WDF_LBA48)
>  		wd->sc_wdc_bio.flags |= ATA_LBA48;
>  	if (wd->sc_flags & WDF_LBA)
>  		wd->sc_wdc_bio.flags |= ATA_LBA;

Doesn't that have the effect of always trying to do LBA48 transfers
on disks that appear to support LBA48 ?

There are two problems:
1) The controller may not support LBA48 (even though the disk does)
2) There is a performance penalty for using LBA48 transfers.
IIRC that is why 28 bit transfers are done whenever possible.

	David

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