Re: [PATCH 12/13] ARM: dts: stm32: fix DSI port node on STM32MP15

[Alexandre TORGUE <alexandre.torgue@xxxxxxxxxxx>]

Hi Ahmad

On 4/15/21 12:43 PM, Ahmad Fatoum wrote:
> Hi,
>
> On 15.04.21 12:10, Alexandre Torgue wrote:
> > Running "make dtbs_check W=1", some warnings are reported concerning
> > DSI. This patch reorder DSI nodes to avoid:
> >
> > soc/dsi@5a000000: unnecessary #address-cells/#size-cells without
> > "ranges" or child "reg" property
>
> This reverts parts of commit 9c32f980d9 ("ARM: dts: stm32: preset
> stm32mp15x video #address- and #size-cells"):
>      
>      The cell count for address and size is defined by the binding and not
>      something a board would change. Avoid each board adding this
>      boilerplate by having the cell size specification in the SoC DTSI.
>      
>
> The DSI can have child nodes with a unit address (e.g. a panel) and ones
> without (ports { } container). ports is described in the dtsi, panels are
> described in the dts if available.
>
> Apparently, the checker is fine with
> ports {
> 	#address-cells = <1>;
> 	#size-cells = <0>;
> };
>
> I think my rationale for the patch above was sound, so I think the checker
> taking offense at the DSI cells here should be considered a false positive.

If it's a "false positive" warning then we need to find a way to not 
print it out. Else, it'll be difficult to distinguish which warnings are 
"normal" and which are not. This question could also be applied to patch[3].

Arnd, Rob what is your feeling about this case ?

thanks
alex



> Thanks,
> Ahmad
>
> > Signed-off-by: Alexandre Torgue <alexandre.torgue@xxxxxxxxxxx>
> >
> > diff --git a/arch/arm/boot/dts/stm32mp157.dtsi b/arch/arm/boot/dts/stm32mp157.dtsi
> > index 54e73ccea446..c355fcf26ec3 100644
> > --- a/arch/arm/boot/dts/stm32mp157.dtsi
> > +++ b/arch/arm/boot/dts/stm32mp157.dtsi
> > @@ -24,8 +24,6 @@
> >   			clock-names = "pclk", "ref", "px_clk";
> >   			resets = <&rcc DSI_R>;
> >   			reset-names = "apb";
> > -			#address-cells = <1>;
> > -			#size-cells = <0>;
> >   			status = "disabled";
> >   
> >   			ports {
> > diff --git a/arch/arm/boot/dts/stm32mp157c-dk2.dts b/arch/arm/boot/dts/stm32mp157c-dk2.dts
> > index 19ef475a48fc..763dde1dbbaf 100644
> > --- a/arch/arm/boot/dts/stm32mp157c-dk2.dts
> > +++ b/arch/arm/boot/dts/stm32mp157c-dk2.dts
> > @@ -36,6 +36,8 @@
> >   &dsi {
> >   	status = "okay";
> >   	phy-dsi-supply = <&reg18>;
> > +	#address-cells = <1>;
> > +	#size-cells = <0>;
> >   
> >   	ports {
> >   		port@0 {
> > diff --git a/arch/arm/boot/dts/stm32mp157c-ev1.dts b/arch/arm/boot/dts/stm32mp157c-ev1.dts
> > index 6fe5b0fee7c4..4625bb58cc6d 100644
> > --- a/arch/arm/boot/dts/stm32mp157c-ev1.dts
> > +++ b/arch/arm/boot/dts/stm32mp157c-ev1.dts
> > @@ -102,6 +102,8 @@
> >   &dsi {
> >   	phy-dsi-supply = <&reg18>;
> >   	status = "okay";
> > +	#address-cells = <1>;
> > +	#size-cells = <0>;
> >   
> >   	ports {
> >   		port@0 {