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Date:   Fri, 23 Sep 2022 11:30:49 +0100
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Subject: Re: [PATCH 6/7] scsi: pm8001: use dev_and_phy_addr_same() instead of
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To:     Jason Yan <yanaijie@huawei.com>, <martin.petersen@oracle.com>,
        <jejb@linux.ibm.com>
CC:     <linux-scsi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <hare@suse.com>, <hch@lst.de>, <bvanassche@acm.org>,
        <jinpu.wang@cloud.ionos.com>
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From:   John Garry <john.garry@huawei.com>
In-Reply-To: <d3c7285f-6318-8254-2bfa-d836f12fcd88@huawei.com>
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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.

 > +}

Thanks,
John