[RFC PATCH net-next] net: dsa: mt7530: rename MT7621 compatible

[Chuanhong Guo]

Hi!

On Sun, Dec 20, 2020 at 1:10 AM Florian Fainelli <f.fainelli at gmail.com> wrote:
>
>
>
> On 12/19/2020 8:26 AM, Andrew Lunn wrote:
> >> --- a/drivers/net/dsa/mt7530.c
> >> +++ b/drivers/net/dsa/mt7530.c
> >> @@ -2688,7 +2688,7 @@ static const struct mt753x_info mt753x_table[] = {
> >>  };
> >>
> >>  static const struct of_device_id mt7530_of_match[] = {
> >> -    { .compatible = "mediatek,mt7621", .data = &mt753x_table[ID_MT7621], },
> >> +    { .compatible = "mediatek,mt7621-gsw", .data = &mt753x_table[ID_MT7621], },
> >>      { .compatible = "mediatek,mt7530", .data = &mt753x_table[ID_MT7530], },
> >>      { .compatible = "mediatek,mt7531", .data = &mt753x_table[ID_MT7531], },
> >>      { /* sentinel */ },
> >
> > This will break backwards compatibility with existing DT blobs. You
> > need to keep the old "mediatek,mt7621", but please add a comment that
> > it is deprecated.
>
> Besides, adding -gsw would make it inconsistent with the existing
> matching compatible strings. While it's not ideal to have the same
> top-level SoC compatible and having another sub-node within that SoC's
> DTS have the same compatible, given this would be break backwards
> compatibility, cannot you stay with what is defined today?

U-boot for MT7621 doesn't support device tree, and the kernel image
is always packaged with dt. Do we need to maintain backward
compatibility at all in this situation?

-- 
Regards,
Chuanhong Guo