[PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[Russell King (Oracle)]

Mark the AXI snps,kbbe snps,mb and snps,rb properties as not
implemented. These were introduced by commit afea03656add ("stmmac:
rework DMA bus setting and introduce new platform AXI structure").
While stmmac has code to parse these properties and save their values,
these are written to write-only struct members - no code in stmmac
has ever read their value. Hence, these properties have been non-
functional from day one.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 Documentation/devicetree/bindings/net/snps,dwmac.yaml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
index 38bc34dc4f09..45dba6533458 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
@@ -202,11 +202,11 @@ title: Synopsys DesignWare MAC
         * snps,xit_frm, unlock on WoL
         * snps,wr_osr_lmt, max write outstanding req. limit
         * snps,rd_osr_lmt, max read outstanding req. limit
-        * snps,kbbe, do not cross 1KiB boundary.
+        * snps,kbbe, do not cross 1KiB boundary (not implemented)
         * snps,blen, this is a vector of supported burst length.
         * snps,fb, fixed-burst
-        * snps,mb, mixed-burst
-        * snps,rb, rebuild INCRx Burst
+        * snps,mb, mixed-burst (not implemented)
+        * snps,rb, rebuild INCRx Burst (not implemented)
 
   snps,mtl-rx-config:
     $ref: /schemas/types.yaml#/definitions/phandle
-- 
2.47.3

Re: [PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[Russell King (Oracle)]

Any chance of a review from the DT maintainers please?

Thanks.

On Wed, Mar 04, 2026 at 05:30:32PM +0000, Russell King (Oracle) wrote:
> Mark the AXI snps,kbbe snps,mb and snps,rb properties as not
> implemented. These were introduced by commit afea03656add ("stmmac:
> rework DMA bus setting and introduce new platform AXI structure").
> While stmmac has code to parse these properties and save their values,
> these are written to write-only struct members - no code in stmmac
> has ever read their value. Hence, these properties have been non-
> functional from day one.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> ---
>  Documentation/devicetree/bindings/net/snps,dwmac.yaml | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> index 38bc34dc4f09..45dba6533458 100644
> --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> @@ -202,11 +202,11 @@ title: Synopsys DesignWare MAC
>          * snps,xit_frm, unlock on WoL
>          * snps,wr_osr_lmt, max write outstanding req. limit
>          * snps,rd_osr_lmt, max read outstanding req. limit
> -        * snps,kbbe, do not cross 1KiB boundary.
> +        * snps,kbbe, do not cross 1KiB boundary (not implemented)
>          * snps,blen, this is a vector of supported burst length.
>          * snps,fb, fixed-burst
> -        * snps,mb, mixed-burst
> -        * snps,rb, rebuild INCRx Burst
> +        * snps,mb, mixed-burst (not implemented)
> +        * snps,rb, rebuild INCRx Burst (not implemented)
>  
>    snps,mtl-rx-config:
>      $ref: /schemas/types.yaml#/definitions/phandle
> -- 
> 2.47.3
> 
> 

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

Re: [PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2338 bytes --]

On Sat, Mar 07, 2026 at 12:05:18AM +0000, Russell King (Oracle) wrote:
> Any chance of a review from the DT maintainers please?

Sure.

> On Wed, Mar 04, 2026 at 05:30:32PM +0000, Russell King (Oracle) wrote:
> > Mark the AXI snps,kbbe snps,mb and snps,rb properties as not
> > implemented. These were introduced by commit afea03656add ("stmmac:
> > rework DMA bus setting and introduce new platform AXI structure").
> > While stmmac has code to parse these properties and save their values,
> > these are written to write-only struct members - no code in stmmac
> > has ever read their value. Hence, these properties have been non-
> > functional from day one.

If they're not implemented and have never been used, could we delete
entirely? Note that they also appear down around line 600 in the file,
in the stmmac-axi-config section.

Cheers,
Conor.

> > 
> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> > ---
> >  Documentation/devicetree/bindings/net/snps,dwmac.yaml | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> > index 38bc34dc4f09..45dba6533458 100644
> > --- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> > +++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
> > @@ -202,11 +202,11 @@ title: Synopsys DesignWare MAC
> >          * snps,xit_frm, unlock on WoL
> >          * snps,wr_osr_lmt, max write outstanding req. limit
> >          * snps,rd_osr_lmt, max read outstanding req. limit
> > -        * snps,kbbe, do not cross 1KiB boundary.
> > +        * snps,kbbe, do not cross 1KiB boundary (not implemented)
> >          * snps,blen, this is a vector of supported burst length.
> >          * snps,fb, fixed-burst
> > -        * snps,mb, mixed-burst
> > -        * snps,rb, rebuild INCRx Burst
> > +        * snps,mb, mixed-burst (not implemented)
> > +        * snps,rb, rebuild INCRx Burst (not implemented)
> >  
> >    snps,mtl-rx-config:
> >      $ref: /schemas/types.yaml#/definitions/phandle
> > -- 
> > 2.47.3
> > 
> > 
> 
> -- 
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[Krzysztof Kozlowski]

On 09/03/2026 18:49, Conor Dooley wrote:
> On Sat, Mar 07, 2026 at 12:05:18AM +0000, Russell King (Oracle) wrote:
>> Any chance of a review from the DT maintainers please?
> 
> Sure.
> 
>> On Wed, Mar 04, 2026 at 05:30:32PM +0000, Russell King (Oracle) wrote:
>>> Mark the AXI snps,kbbe snps,mb and snps,rb properties as not
>>> implemented. These were introduced by commit afea03656add ("stmmac:
>>> rework DMA bus setting and introduce new platform AXI structure").
>>> While stmmac has code to parse these properties and save their values,
>>> these are written to write-only struct members - no code in stmmac
>>> has ever read their value. Hence, these properties have been non-
>>> functional from day one.
> 
> If they're not implemented and have never been used, could we delete
> entirely? Note that they also appear down around line 600 in the file,
> in the stmmac-axi-config section.
> 

We should not document what is and what is not implemented, thus this
patch is not correct either. Either you deprecate properties, based on
some argument, or you leave them untouched regardless whether they are
implemented or not. If someone re-implements them next week, are you
going to change the binding? Usually no, unless these are not really
hardware properties.

Best regards,
Krzysztof

Re: [PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[Krzysztof Kozlowski]

On 10/03/2026 09:43, Krzysztof Kozlowski wrote:
> On 09/03/2026 18:49, Conor Dooley wrote:
>> On Sat, Mar 07, 2026 at 12:05:18AM +0000, Russell King (Oracle) wrote:
>>> Any chance of a review from the DT maintainers please?
>>
>> Sure.
>>
>>> On Wed, Mar 04, 2026 at 05:30:32PM +0000, Russell King (Oracle) wrote:
>>>> Mark the AXI snps,kbbe snps,mb and snps,rb properties as not
>>>> implemented. These were introduced by commit afea03656add ("stmmac:
>>>> rework DMA bus setting and introduce new platform AXI structure").
>>>> While stmmac has code to parse these properties and save their values,
>>>> these are written to write-only struct members - no code in stmmac
>>>> has ever read their value. Hence, these properties have been non-
>>>> functional from day one.
>>
>> If they're not implemented and have never been used, could we delete

Maybe I misunderstood, did you mean delete from the drivers as well?
This would work as well, but we cannot only remove the dt-bindings.


>> entirely? Note that they also appear down around line 600 in the file,
>> in the stmmac-axi-config section.
>>
> 
> We should not document what is and what is not implemented, thus this
> patch is not correct either. Either you deprecate properties, based on
> some argument, or you leave them untouched regardless whether they are
> implemented or not. If someone re-implements them next week, are you
> going to change the binding? Usually no, unless these are not really
> hardware properties.



Best regards,
Krzysztof

Re: [PATCH] dt-bindings: mark unimplemented AXI snps,kbbe snps,mb and snps,rb

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1753 bytes --]

On Tue, Mar 10, 2026 at 09:48:25AM +0100, Krzysztof Kozlowski wrote:
> On 10/03/2026 09:43, Krzysztof Kozlowski wrote:
> > On 09/03/2026 18:49, Conor Dooley wrote:
> >> On Sat, Mar 07, 2026 at 12:05:18AM +0000, Russell King (Oracle) wrote:
> >>> Any chance of a review from the DT maintainers please?
> >>
> >> Sure.
> >>
> >>> On Wed, Mar 04, 2026 at 05:30:32PM +0000, Russell King (Oracle) wrote:
> >>>> Mark the AXI snps,kbbe snps,mb and snps,rb properties as not
> >>>> implemented. These were introduced by commit afea03656add ("stmmac:
> >>>> rework DMA bus setting and introduce new platform AXI structure").
> >>>> While stmmac has code to parse these properties and save their values,
> >>>> these are written to write-only struct members - no code in stmmac
> >>>> has ever read their value. Hence, these properties have been non-
> >>>> functional from day one.
> >>
> >> If they're not implemented and have never been used, could we delete
> 
> Maybe I misunderstood, did you mean delete from the drivers as well?

Correct. That's what I meant by "delete entirely".

> This would work as well, but we cannot only remove the dt-bindings.
> 
> 
> >> entirely? Note that they also appear down around line 600 in the file,
> >> in the stmmac-axi-config section.
> >>
> > 
> > We should not document what is and what is not implemented, thus this
> > patch is not correct either. Either you deprecate properties, based on
> > some argument, or you leave them untouched regardless whether they are
> > implemented or not. If someone re-implements them next week, are you
> > going to change the binding? Usually no, unless these are not really
> > hardware properties.
> 
> 
> 
> Best regards,
> Krzysztof

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]