Re: WD_QUIRK_FORCE_LBA48

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Tue, Dec 15, 2009 at 08:08:57AM +0000, Michael van Elst wrote:
> bouyer%antioche.eu.org@localhost (Manuel Bouyer) writes:
> 
> Hi Manuel,
> 
> >> Actually I think someone pointed out that the max sector number
> >> for LBA28 is sector 0xffffffe - the maximum value for the 'number of
> >> sectors addressable with LBA28' is 0xfffffff.
> 
> >that's true in ATA7. but previous standards didn't impose restrictions
> >on the content of words 60-61 of IDENTIFY, nor did they state that
> >LBA28's last sector is 0xfffffe.
> 
> ATA6 (at least the draft I have) shows the same rules and ATA5
> doesn't have LBA48.

Yes that's more or less what I meant. ATA6 says that words 60-61
should be less than or equal to 0x10000000, which means we can address
sectors 0-0xfffffff using LBA28.
This changed in ATA7 to be one less sector (no idea why they did this).

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--