Subject: Re: [PATCH 0/2] mv88e6xxx: Poll when no interrupt defined

From: Andrew Lunn <[email-masked]>
Date: Tue, 27 Feb 2018 15:07:07 +0100

On Tue, Feb 27, 2018 at 11:24:02AM +0100, Gregory CLEMENT wrote:
> Hi Andrew,
>  
>  On jeu., fï¿½vr. 22 2018, Andrew Lunn <[email-masked]> wrote:
> 
> > Not all boards using the mv88e6xxx switches have the interrupt output
> > connected to a GPIO. On these boards phylib has to poll the PHYs,
> > rather than use interrupts. Have the driver poll the interrupt status
> > register, which is more efficient than having phylib do it. And it
> > enables other switch interrupts to be services.
> >
> > The Armada 370RD is such a board without a interrupt GPIO. Now that
> > interrupts work, wire up the PHYs to make use if them.
> >
> > Gregory: Are you O.K. for the second patch to go through netdev?
> 
> Why do you need that the second patch to go through netdev. Is there any
> dependency between the 2 patches?
> 
> If it is the case does it means that an new kernel won't work with an
> old device tree?

Hi Gregory

There is a runtime dependency between the two. A new device tree blob
will not run on an old kernel. So if you take the second patch alone
via mvebu, the PHYs will stop working, no link up reported.

But an old blob will run on a new kernel. Backwards compatibility is
maintained.

	Andrew