Re: [PATCH] path_id: Re-introduce SAS phy enumeration of devices

[Nils Carlson <nils.carlson@ericsson.com>]

Hi Hannes,

On 04/02/2012 03:35 PM, Hannes Reinecke wrote:
> Hi Nils,
>
> Thanks a lot for this. It definitely a step in the correct
> direction. However, I have some comments to make:
>
> On 04/02/2012 02:56 PM, Nils Carlson wrote:
>> where phy0:1 is the reintroduced substring where 0 corresponds
>> to the lowest phy identifier on the port to which the device
>> is connected and 1 is the number of phys on the port.
>>
> I would rather not do this.
> First of all, I doubt we need the overall number of phys here.
> Secondly, James B. assured me that the phy enumeration is pretty much
> stable, so we should be able to use that number as-is.

I agree this would be clean, the problem is that it represents an API 
change; one could argue though that that API change has already been 
made through the breakage though.

> Also, there is a 1:1 match between the 'phy_identifier' sysfs attribute
> and the second number of the phy name itself (the first number is the
> SCSI host number), so we could as well just parse the phy name and get
> the number from there.
> But, of course, reading the phy_identifier is okay, too

Yes, this would of course also work, though I think reading the 
phy_identifier is cleaner.
.
>
> So I would propose just to insert a 'phy1' there.

I will need to check that nobody has coded the phyX:Y format into any 
scripts, hopefully the answer is no.

Cheers,
Nils