Re: [PATCH RFC 3/9] net: stmmac: qcom-ethqos: fix RGMII_ID mode to use DLL bypass

[Andrew Lunn]

> > With this in mind, I was thinking of breaking up this patch series into
> > separate ones to solve one problem at a time:
> > 
> >  1. Introduce support for "rgmii-id" using PHY-side delays rather than
> >  MAC-provided delays. Also, issue a warning if any other phy-mode is
> >  being used.
> > 
> >  2. Fix the DTS of the existing boards to use "rgmii-id".
> > 
> >  3. Once the DTS is fixed, remove the now-unused code handling non
> >  RGMII-ID cases. This should also allow us to remove the whole
> >  ethqos_emac_por code since it wouldn't be needed for RGMII-ID.
> 
> I'm wondering if we should add some temporary very loud warning for
> boards that use "rgmii" before changing this, or even just keep the
> actual "rgmii" behaviour which inserts the delays, as there seems to
> be lots of such users...

We cannot break in tree users, and backwards compatibility with old
mainline DT blobs is required. So for those, we need 'rgmii' to
continue to work as is.

So steps 1 and 2 are correct. But we cannot do 3. 

We can however issue a warning when 'rgmii' is used, advising users to
upgrade to a newer DT blob.

	Andrew