[PATCH v2 1/4] ARM: dts: sun8i: r40: add /omit-if-no-ref/ to pinmux nodes for UARTs 0&3

[Ivan Uvarov]

On Mon, 22 Mar 2021 16:18:04 +0000
Andre Przywara <andre.przywara at arm.com> wrote:

> On Mon, 22 Mar 2021 13:55:35 +0300
> Ivan Uvarov <i.uvarov at cognitivepilot.com> wrote:
> 
> Hi,
>   
> > This patch adds the /omit-if-no-ref/ keyword to the pio nodes for
> > UART0 and UART3 pins of the R40 SoC, which would reduce the fdt
> > size on boards which do not use these UARTs.    
> 
> But what boards are those? It seems like all boards use uart3-pg and
> the two existing boards use UART0.
> 
> I think the idea is to use omit-if-no-ref on some rarely used nodes,
> so if there is only a single user, for instance. Your next patch is a
> good example.
> 
> So I don't think this patch here is needed at all.
> 
> Cheers,
> Andre
>   

This is a valid complaint, and the patch indeed is not strictly
necessary. At the same time, the keyword certainly doesn't hurt, and
it would be a good base for future R40 boards. 

As to what boards I'm referring to, there's at least the carrier board
for the FETA40i which our company is privately developing, the support
for which we probably won't upstream as it's highly unlikely it'll ever
get into the hands of anyone who would appreciate such support.

I must also mention that I only added this patch to the series due to
explicit encouragement from Maxime in his last response to v1 of the patch:

On Fri, 19 Mar 2021 14:24:48 +0100 
Maxime Ripard <maxime at cerno.tech> wrote:
> On Tue, Mar 16, 2021 at 06:48:58PM +0300, Ivan Uvarov wrote:  
> > Also, would it be a good idea to add /omit-if-no-ref/ to the uart3
> > pins as well while I'm here?   
>
> To all the nodes honestly. If you want to make a preliminary patch doing
> this, go ahead :)  

Since there's two differing viewpoints on the subject, this definitely
deserves more discussion.

--
Regards,
Ivan Uvarov