Re: [PATCH RFT 2/2] macb: kill PHY reset code

From: Andrew Lunn
Date: Mon Apr 11 2016 - 14:51:23 EST


On Mon, Apr 11, 2016 at 09:39:02PM +0300, Sergei Shtylyov wrote:
> Hello.
>
> On 04/11/2016 09:19 PM, Andrew Lunn wrote:
>
> >>>The code you are deleting would of ignored the flags in the gpio
> >>>property, i.e. active low.
> >>
> >> Hm, you're right -- I forgot about that... :-/
> >>
> >>>The new code in the previous patch does
> >>>however take the flags into account. Did you check if there are any
> >>>device trees which have flags, which were never used, but are now
> >>>going to be used and thus break...
> >>
> >> Checked this now and found out arch/arm/boot/dts/ar91-vinco.dts.
> >>Looks like it needs to be fixed indeed...
> >>
> >And this is where it gets tricky. You are breaking backwards
> >compatibility by now respecting the flag. An old DT blob is not going
> >to work.
>
> Do we care that much about the DT blobs that are just *wrong*?

Wrong, but currently works.

> >You potentially need to add a new property and deprecate the old one.
>
> I would like to avoid that...

You will need the agreement from the at91-vinco maintainer.

Andrew