Re: [PATCH] net: phy: micrel: remove suspend/resume

[Christophe Leroy]

Le 26/08/2016 Ã 06:35, Florian Fainelli a Ãcrit :
> Le 24/08/2016 Ã 07:14, Christophe Leroy a Ãcrit :
> > Le 23/08/2016 Ã 21:03, Florian Fainelli a Ãcrit :
> > > +others,
> > >
> > > On 08/23/2016 04:13 AM, Christophe Leroy wrote:
> > > > In ERRATA DS80000700A dated 05 May 2016, Microship recommends to
> > > > not use software power down mode on KSZ8041 family.
> > >
> > > s/Microship/Microchip/
> > >
> > > > They say they have no plan to fix this ERRATA in future releases.
> > >
> > > The errata applies to specific revisions, is this revision present in
> > > the lower 4 bits of the MII_PHYSID2 register such that it could be used
> > > to key the disabling of the power down?
> >
> > It doesn't seem clear to me how this could/should be handled.
> >
> > According to the documentation, all variants have the same ID 0x0022151x
> > with revision x. A3 has ID 0x00221512 and A4 has 0x00221513.
> > According to the doc, the KSZ8041RNLI should has same ID. But according
> > to micrel driver, it has ID 0x00221537. And the buggy revision of that
> > one is rev A. Is it what the 7 means ?
>
> Humm the revision is typically stored on 4 bits, so 0x7 could mean
> anything here, it really depends if how they are allocating their revision.
>
> 0b0000 -> A0
> 0b0001 -> A1
> ...
> 0b0110 -> A6
> 0b0111 -> A7?
>
> Who knows.
>
> > The ERRATA applies to KSZ8041NL revision A4 and to KSZ8041NL-AM revision
> > A3. My understanding it that both variants have ID 0x0022151x, ie
> > KSZ8041NL-AM revision A3 has ID 0x00221512 and KSZ8041NL revision A4 has
> > ID 0x00221513. But KSZ8041NL revision A3 also has ID 0x00221512 and the
> > ERRATA doesn't apply to it.
> >
> > So what can be done really ? Only apply the fix to ID 0x00221513 (which
> > is what I need as I have KSZ8041NL revision A4 on my boards) ? Or apply
> > it for all KSZ8041 and KSZ8041RNLI to be on the safe side ?
>
> I would apply it to just the KSZ8041NL rev. A4 for now, ideally we would
> want to track down the users of the KSZ8041RNLI and see if somebody
> could test that, realistically, we won't be able to, so I would err on
> the side of caution at the expense of slightly increased power
> consumption for that particular PHY and have a broader match of all the
> KSZ8041RNLI potentially affected.
>
> Does that make sense?

What about the KSZ8041NL-AM revision A3, which has the same PHY ID as 
the KSZ8041NL revision A3 ?
Shouldn't we also have a broader match on this one in order to cover all 
cases and also be on the side of caution ?

Christophe