Re: [PATCH 2/2] ata: libata-sata: Simplify sense_valid fetching

Niklas Cassel
2025-04-15T07:34:57Z

On Tue, Apr 15, 2025 at 08:51:46AM +0200, Hannes Reinecke wrote:
> On 4/11/25 15:25, Niklas Cassel wrote:
> > While the sense_valid field is 47 bits according to the specification,
> > we are currently only fetching 32 bits, because these are the only
> > bits that represent the tags (0-31), which is all we care about.
> >
> > Thus, replace the existing logic with a simple get_unaligned_le32().
> >
> > Signed-off-by: Niklas Cassel <cassel@kernel.org>
> > ---
> > drivers/ata/libata-sata.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
> > index 2e4463d3a356..5ba79a1053ea 100644
> > --- a/drivers/ata/libata-sata.c
> > +++ b/drivers/ata/libata-sata.c
> > @@ -1529,8 +1529,7 @@ int ata_eh_get_ncq_success_sense(struct ata_link *link)
> > return -EIO;
> > }
> > - sense_valid = (u64)buf[8] | ((u64)buf[9] << 8) |
> > - ((u64)buf[10] << 16) | ((u64)buf[11] << 24);
> > + sense_valid = get_unaligned_le32(&buf[8]);
> > extended_sense = get_unaligned_le16(&buf[14]);
> > aux_icc_valid = extended_sense & BIT(15);
>
> Description is ever so misleading; we never fetched 47 bits to start
> with. All we do is simplify the logic.
> But whatever.

IMO, that is exactly what I wrote :)

Nevertheless, I clarified the commit message in V2.

Kind regards,
Niklas