Re: [PATCH 1/2] of_mdio: add new DT property 'link' for fixed-link

On 10/07/15 04:20, Stas Sergeev wrote:

10.07.2015 11:46, Sebastien Rannou пишет:

quoted

On Fri, 10 Jul 2015, Stas Sergeev wrote:

quoted

10.07.2015 00:15, Florian Fainelli пишет:

quoted

Then, if the in-band status indication is not reliable (which really
should be completely understood),

Agree!
But this is not something I can help with.
Sebastien Rannou reports the problem, please ask him whatever
you see fits to get a better understanding of a problem.
The fact that his HW does not generate the inband status, is
_my own guess_.

Yes, I confirm that my HW does not generate an in-band status. AFAIK, it's
a PHY that aggregates 4xSGMIIs to 1xQSGMII ; the MAC side of the PHY (with
inband status) is connected to the switch through QSGMII, and in this context
we are on the media side of the PHY.

Hmm, interesting.
So if I parse the above correctly, you have something like 88E1340S set
up into a mode when SGMII is used as media interface and QSGMII as system
interface (terms are from datasheet page 5), then you connect the media
interface to armada-xp and system interface to the switch.

I wonder if it is the right thing to do.
AFAIK you could as well set up armada-xp into QSGMII mode and connect
that to switch. The driver would then disable the use of inband status
and everything would be fine.
Either way, your use-case proves that only DT can decide the use of an
inband status.

I do not think there is any debate around the need for a property that
defines whether in-band-status is both reliable and usable, the debate
is about *where* to put it.

I still think this does not belong in the fixed-link property, but now
that you have explained a bit more in the other patch what your
understanding of "fixed-link" is, I can see the confusion.

Instead of having a link = "auto", property, how about just something
like this:

fixed-link {
	speed = <1000>;
	full-duplex;
	use-in-band-status;
};

or event this:

fixed-link {
	use-in-band-status;
};

If you parse the 'use-in-band-status' which means that it is reliable
information, then you can override whatever was defined in the DT under
the 'fixed-link' property?
-- 
Florian