Re: [PATCH v3 1/6] ata: libata-scsi: Fix offsets for the fixed format sense data

[Igor Pylypiv <ipylypiv@google.com>]

On Fri, Jun 28, 2024 at 08:25:40PM +0200, Niklas Cassel wrote:
> On Fri, Jun 28, 2024 at 05:49:22PM +0200, Niklas Cassel wrote:
> > On Fri, Jun 28, 2024 at 08:47:03AM +0200, Hannes Reinecke wrote:
> > > On 6/27/24 14:08, Niklas Cassel wrote:
> > 
> > In SAT-6 there is no mention of compliance with ANSI INCITS 431-2007 should
> > ignore D_SENSE bit and unconditionally return sense data in descriptor format.
> > 
> > Anyway, considering that:
> > 1) I'm not sure how a SAT would expose that it is compliant with ANSI INCITS
> >    431-2007.
> > 2) This text has been removed from SAT-6.
> > 3) We currently honour the D_SENSE bit when creating the sense buffer with the
> >    SK/ASC/ASCQ that we get from the device.
> > 
> > I think that it makes sense to honour the D_SENSE bit also when generating
> > sense data for successful ATA PASS-THROUGH commands (from ATA registers).
> 
> Igor, I think you should add a new patch in your series that does:

Thanks Niklas, I'll add the patch in v4.

> 
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index d5874d4b9253..5b211551ac10 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -949,11 +949,8 @@ static void ata_gen_passthru_sense(struct ata_queued_cmd *qc)
>                                    &sense_key, &asc, &ascq);
>                 ata_scsi_set_sense(qc->dev, cmd, sense_key, asc, ascq);
>         } else {
> -               /*
> -                * ATA PASS-THROUGH INFORMATION AVAILABLE
> -                * Always in descriptor format sense.
> -                */
> -               scsi_build_sense(cmd, 1, RECOVERED_ERROR, 0, 0x1D);
> +               /* ATA PASS-THROUGH INFORMATION AVAILABLE */
> +               ata_scsi_set_sense(qc->dev, cmd, RECOVERED_ERROR, 0, 0x1D);
>         }
>  }
> 
> 
> Feel free to copy my arguments above.
> 
> I also checked VPD page 89h (ATA Information VPD page), and there are
> no bits there either to claim certain SAT version compliance.
> 
> And since this text is not in SAT-6, I can only imagine that they decided
> that is was not a good idea to not always honor D_SENSE...
> 
> (It does seem simpler to just always honor it...)
> 
> 
> Kind regards,
> Niklas