quoted

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... :-/

quoted

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.

You potentially need to add a new property and deprecate the old one.

    Andrew