The CM3.5 used on EyeQ6 reports that Hardware Cache Initialization is
complete, but in reality it's not the case. It also incorrectly
indicates that Hardware Cache Initialization is supported. This new
compatible string allows warning about this broken feature that cannot
be detected at runtime.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 Documentation/devicetree/bindings/mips/mti,mips-cm.yaml | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml b/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
index 4324b2306535f1bf66c44b1f96be9094ee282041..d129d6382847768dc026336d8d2c7328b6b81f9b 100644
--- a/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
+++ b/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
@@ -19,7 +19,12 @@ maintainers:
 
 properties:
   compatible:
-    const: mti,mips-cm
+    oneOf:
+      - const: mti,mips-cm
+      - const: mobileye,eyeq6-cm
+        description:
+          On EyeQ6 the HCI (Hardware Cache Initialization) information for
+          the L2 cache in multi-cluster configuration is broken.
 
   reg:
     description:
@@ -44,4 +49,9 @@ examples:
       compatible = "mti,mips-cm";
       reg = <0x1bde8000 0x8000>;
     };
+
+  - |
+    coherency-manager {
+      compatible = "mobileye,eyeq6-cm";
+    };
 ...

-- 
2.45.2

在2025年1月23日一月 上午11:01，Gregory CLEMENT写道：
> The CM3.5 used on EyeQ6 reports that Hardware Cache Initialization is
> complete, but in reality it's not the case. It also incorrectly
> indicates that Hardware Cache Initialization is supported. This new
> compatible string allows warning about this broken feature that cannot
> be detected at runtime.
>
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>  Documentation/devicetree/bindings/mips/mti,mips-cm.yaml | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml 
> b/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> index 
> 4324b2306535f1bf66c44b1f96be9094ee282041..d129d6382847768dc026336d8d2c7328b6b81f9b 
> 100644
> --- a/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> +++ b/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> @@ -19,7 +19,12 @@ maintainers:
> 
>  properties:
>    compatible:
> -    const: mti,mips-cm
> +    oneOf:
> +      - const: mti,mips-cm
> +      - const: mobileye,eyeq6-cm
> +        description:
> +          On EyeQ6 the HCI (Hardware Cache Initialization) information for
> +          the L2 cache in multi-cluster configuration is broken.
> 
>    reg:
>      description:
> @@ -44,4 +49,9 @@ examples:
>        compatible = "mti,mips-cm";
>        reg = <0x1bde8000 0x8000>;
>      };
> +
> +  - |
> +    coherency-manager {
> +      compatible = "mobileye,eyeq6-cm";

I think “mobileye,eyeq6-cm”, “mti,mips-cm” would describe the hardware better as eyeq6’s CM is just a special variant of mips-cm.

But I’m fine with leaving it as is.


Thanks

> +    };
>  ...
>
> -- 
> 2.45.2

-- 
- Jiaxun

On Mon, Jan 27, 2025 at 3:43 PM Jiaxun Yang <jiaxun.yang@flygoat.com> wrote:
>
>
>
> 在2025年1月23日一月 上午11:01，Gregory CLEMENT写道：
> > The CM3.5 used on EyeQ6 reports that Hardware Cache Initialization is
> > complete, but in reality it's not the case. It also incorrectly
> > indicates that Hardware Cache Initialization is supported. This new
> > compatible string allows warning about this broken feature that cannot
> > be detected at runtime.
> >
> > Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> > ---
> >  Documentation/devicetree/bindings/mips/mti,mips-cm.yaml | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> > b/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> > index
> > 4324b2306535f1bf66c44b1f96be9094ee282041..d129d6382847768dc026336d8d2c7328b6b81f9b
> > 100644
> > --- a/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> > +++ b/Documentation/devicetree/bindings/mips/mti,mips-cm.yaml
> > @@ -19,7 +19,12 @@ maintainers:
> >
> >  properties:
> >    compatible:
> > -    const: mti,mips-cm
> > +    oneOf:
> > +      - const: mti,mips-cm
> > +      - const: mobileye,eyeq6-cm
> > +        description:
> > +          On EyeQ6 the HCI (Hardware Cache Initialization) information for
> > +          the L2 cache in multi-cluster configuration is broken.
> >
> >    reg:
> >      description:
> > @@ -44,4 +49,9 @@ examples:
> >        compatible = "mti,mips-cm";
> >        reg = <0x1bde8000 0x8000>;
> >      };
> > +
> > +  - |
> > +    coherency-manager {
> > +      compatible = "mobileye,eyeq6-cm";
>
> I think “mobileye,eyeq6-cm”, “mti,mips-cm” would describe the hardware better as eyeq6’s CM is just a special variant of mips-cm.

Is s/w that only understands “mti,mips-cm” useful on eyeq6 chip? If
so, I agree. If not, then a fallback compatible is not useful.

Rob

On Thu, 23 Jan 2025 12:01:55 +0100, Gregory CLEMENT wrote:
> The CM3.5 used on EyeQ6 reports that Hardware Cache Initialization is
> complete, but in reality it's not the case. It also incorrectly
> indicates that Hardware Cache Initialization is supported. This new
> compatible string allows warning about this broken feature that cannot
> be detected at runtime.
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>  Documentation/devicetree/bindings/mips/mti,mips-cm.yaml | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>