Re: [PATCH 6/7] scsi: pm8001: use dev_and_phy_addr_same() instead of open coded

[Jason Yan]

On 2022/9/23 18:30, John Garry wrote:
> On 23/09/2022 11:13, Jason Yan wrote:
> > > Please explain why.
> > >
> > > I would assume that if those helpers were only used in libsas code 
> > > (and not LLDDs) then they could be put in sas_internal.h and no need 
> > > for export
> >
> >
> > Sorry, I did not make it clear. I mean we need to export 
> > sas_find_attathed_phy() below. Not the sas address comparation helpers.
>
> That seems fine to me.
>
> About sas_find_attathed_phy() implementation,
>
>  > +static inline int sas_find_attathed_phy(struct expander_device *ex_dev,
>  > +                                       struct domain_device *dev)
>  > +{
>  > +       struct ex_phy *phy;
>  > +       int phy_id;
>  > +
>  > +       for (phy_id = 0; phy_id < ex_dev->num_phys; phy_id++) {
>  > +               phy = &ex_dev->ex_phy[phy_id];
>  > +               if (SAS_ADDR(phy->attached_sas_addr)
>  > +                       == SAS_ADDR(dev->sas_addr))
>  > +                       return phy_id;
>  > +       }
>  > +
>  > +       return ex_dev->num_phys;
>
> Returning ex_dev->num_phys would seem ok, but then the LLDD needs to 
> check that return against ex_dev->num_phys. It seems ok, but I'm still 
> not 100% comfortable with that. Maybe returning -ENODEV may be better.
>
> Or return boolean and pass phy_id as pointer to be filled in when 
> returning true.

I've been thinking about this for a while too. Thank you for the advise.

Thanks,
Jason

>  > +}
>
> Thanks,
> John
>
> .