Re: [PATCH V5 1/5] dt-bindings: serial: meson: Drop legacy compatible.

[Rob Herring]

On Mon, Jan 10, 2022 at 4:42 AM Yu Tu <yu.tu@xxxxxxxxxxx> wrote:
>
> Deprecated, don't use anymore because legacy amlogic,meson-gx-uart
> compatible. Don't differentiate between GXBB, GXL and G12A which
> have different revisions of the UART IP. So it's split into
> GXBB,GXL and G12A.

You are breaking compatibility. If your dts is updated to use the new
compatible, then a kernel without the change will not work anymore. It
worked before without understanding the changes you are making. It
should continue to. A compatible value like this would accomplish what
you want:

"amlogic,meson-gxbb-uart", "amlogic,meson-gx-uart", "amlogic,meson-ao-uart"

A new kernel will match on "amlogic,meson-gxbb-uart" or
"amlogic,meson-gx-uart" depending if the dtb is updated or not. An old
kernel will continue to match on "amlogic,meson-gx-uart".

If you are going to go breaking things, the power domain distinction
in the compatible is odd...


Rob