Re: WD_QUIRK_FORCE_LBA48

[mlelstv%serpens.de@localhost (Michael van Elst)]

bouyer%antioche.eu.org@localhost (Manuel Bouyer) writes:

>That there are drives out there, which claim LBA48 support but are
>otherwise conform to the ATA-5 standart (not ATA-6) and so support
>reading sector 0xfffffff using LBA28. If you use the "clamp to 128GB"
>jumper they will report a capacity of 0x10000000 and not 0xfffffff.
>Of course such drives are old enough to be connected to a controller
>which is old enough to not work properly with LBA48.

Which means, we are seeking support to access 2 more sectors
for broken (or say: nonstandard) drives that are artificially
limited to work with broken controllers.

Do you know a way to detect such a controller? Seems to be a
more reasonable approach than to deduce behaviour from
a rather imprecise standard.

N.B. for the specific drives you described a simple quirk would be
to ignore the LBA48 capability if a drive reports a standard <= ATA-5
and capacity <= 2^28. The decision logic for LBA48 transfers
would simply not be used and everything would be addressed
by LBA28.

-- 
-- 
                                Michael van Elst
Internet: mlelstv%serpens.de@localhost
                                "A potential Snark may lurk in every tree."