Re: [PATCH v6 2/2] scsi: libsas: Add linkrate and sas_addr change detection in rediscover

[yangxingui]

On 2026/6/10 17:37, John Garry wrote:
> On 03/06/2026 10:21, Xingui Yang wrote:
> > +        return false;
> > +    } else if (SAS_ADDR(child_dev->sas_addr) != 
> > SAS_ADDR(phy->attached_sas_addr)) {
> > +        pr_info("ex %016llx phy%02d sas_addr changed from %016llx to 
> > %016llx\n",
> > +            SAS_ADDR(dev->sas_addr), phy_id,
> > +            SAS_ADDR(child_dev->sas_addr),
> > +            SAS_ADDR(phy->attached_sas_addr));
> > +        memcpy(phy->attached_sas_addr, child_dev->sas_addr, 
> > SAS_ADDR_SIZE);
>
> can you comment in the code why you are going this?

Good point. I will add a comment explaining the reason.

sas_ex_phy_discover() has already updated phy->attached_sas_addr to the
new address discovered from the expander. However, 
sas_unregister_devs_sas_addr()
matches devices by comparing child->sas_addr with phy->attached_sas_addr
via sas_phy_match_dev_addr(). So we need to restore phy->attached_sas_addr
to the old device's address for proper matching.

I will update in next version.

Thanks,
Xingui