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

From: Yu Tu
Date: Tue Jan 11 2022 - 02:18:18 EST


Hi Rob,
Thank you very much for your reply.

On 2022/1/11 0:18, Rob Herring wrote:
[ EXTERNAL EMAIL ]

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...

I will not blindly delete this "amlogic, meson-gx-uart" compatible as you suggest, just make a comment until all DTS changes are finished.

Rob