Re: [RFC/PATCH] libata and bogus LBA48 drives

[Jeff Garzik <jeff@garzik.org>]

Geert Uytterhoeven wrote:
> 	Hi Jeff,
> 
> A colleague noticed recent versions of Ubuntu no longer detect his 80 GB
> ST380020ACE drive. This drive is special in that it advertises LBA48 support,
> but has the lba_capacity_2 field set to zero (cfr.
> http://lkml.org/lkml/2004/3/30/163).
> 
> Upon closer look, libata indeed doesn't seem to handle this case yet.
> Below is an (untested) fix.
> 
> ---
> Subject: libata: Ignore bogus lba48 drives
> 
> Some drives (e.g. the 80 GB ST380020ACE) advertise they support LBA48, but have
> lba_capacity_2 field set to zero. This causes the drive not being detected by
> the libata driver.
> 
> Add a check for this to ata_id_has_lba48(), cfr. what is done in
> idedisk_supports_lba48().
> 
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
> ---
> NOTE: Untested due to the lack of hardware
> 
>  include/linux/ata.h |    2 ++
>  1 file changed, 2 insertions(+)
> 
> --- a/include/linux/ata.h
> +++ b/include/linux/ata.h
> @@ -402,6 +402,8 @@ static inline int ata_id_has_lba48(const
>  {
>  	if ((id[83] & 0xC000) != 0x4000)
>  		return 0;
> +	if (!ata_id_u64(id, 100))
> +		return 0;
>  	return id[83] & (1 << 10);
>  }

Is there any hope of getting a dump of the IDENTIFY DEVICE page?

'hdparm --Istdout /dev/DEVICE' should do the trick, for either IDE 
driver or libata.

	Jeff