Date:   Wed, 21 Dec 2022 10:36:48 +0100
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Devarsh Thakkar <devarsht@...com>, andersson@...nel.org,
        mathieu.poirier@...aro.org, p.zabel@...gutronix.de,
        linux-remoteproc@...r.kernel.org, linux-kernel@...r.kernel.org,
        devicetree@...r.kernel.org, s-anna@...com
Cc:     robh+dt@...nel.org, krzysztof.kozlowski+dt@...aro.org,
        hnagalla@...com, praneeth@...com, nm@...com, vigneshr@...com,
        a-bhatia1@...com, j-luthra@...com
Subject: Re: [PATCH v2 1/2] Documentation: dt-bindings: k3-r5f-rproc: Add new
 compatible for AM62 SoC family

On 21/12/2022 08:42, Devarsh Thakkar wrote:
> Hi Krzysztof,
> 
> Thanks for the review. Please find my response inline.
> 
> On 30/11/22 20:33, Krzysztof Kozlowski wrote:
>> On 30/11/2022 14:40, Devarsh Thakkar wrote:
>>> AM62 family of devices don't have a R5F cluster, instead
>>> they have single core DM R5F.
>>> Add new compatible string ti,am62-r5fss to support this scenario.
>>>
>>> When this new compatible is used don't allow cluster-mode
>>> property usage in device-tree as this implies that there
>>> is no R5F cluster available and only single R5F core
>>> is present.
>>>
>>> Signed-off-by: Devarsh Thakkar <devarsht@...com>
>>> ---
>>> V2: Avoid acronyms, use "Device Manager" instead of "DM"
>>
>> Use subject prefixes matching the subsystem (git log --oneline -- ...).
> Agreed, I will update the prefix as dt-bindings: remoteproc: k3-r5f: in V3.
>>
>>> ---
>>>  .../bindings/remoteproc/ti,k3-r5f-rproc.yaml  | 48 +++++++++++++------
>>>  1 file changed, 34 insertions(+), 14 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>> index fb9605f0655b..91357635025a 100644
>>> --- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>> +++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
>>> @@ -21,6 +21,9 @@ description: |
>>>    called "Single-CPU" mode, where only Core0 is used, but with ability to use
>>>    Core1's TCMs as well.
>>>  
>>> +  AM62 SoC family support a single R5F core only which runs Device Manager
>>> +  firmware and can also be used as a remote processor with IPC communication.
>>> +
>>>    Each Dual-Core R5F sub-system is represented as a single DTS node
>>>    representing the cluster, with a pair of child DT nodes representing
>>>    the individual R5F cores. Each node has a number of required or optional
>>> @@ -28,6 +31,9 @@ description: |
>>>    the device management of the remote processor and to communicate with the
>>>    remote processor.
>>>  
>>> +  Since AM62 SoC family only support a single core, there is no cluster-mode
>>> +  property setting required for it.
>>> +
>>>  properties:
>>>    $nodename:
>>>      pattern: "^r5fss(@.*)?"
>>> @@ -38,6 +44,7 @@ properties:
>>>        - ti,j721e-r5fss
>>>        - ti,j7200-r5fss
>>>        - ti,am64-r5fss
>>> +      - ti,am62-r5fss
>>
>> Some order? Alphabetical, so before am64? Same in other places.
> Agreed, I will update in V3 accordingly.
>>
>>
>>>        - ti,j721s2-r5fss
>>>  
>>>    power-domains:
>>> @@ -80,7 +87,8 @@ patternProperties:
>>>        node representing a TI instantiation of the Arm Cortex R5F core. There
>>>        are some specific integration differences for the IP like the usage of
>>>        a Region Address Translator (RAT) for translating the larger SoC bus
>>> -      addresses into a 32-bit address space for the processor.
>>> +      addresses into a 32-bit address space for the processor. For AM62x,
>>> +      should only define one R5F child node as it has only one core available.
>>>  
>>>        Each R5F core has an associated 64 KB of Tightly-Coupled Memory (TCM)
>>>        internal memories split between two banks - TCMA and TCMB (further
>>> @@ -104,6 +112,7 @@ patternProperties:
>>>            - ti,j721e-r5f
>>>            - ti,j7200-r5f
>>>            - ti,am64-r5f
>>> +          - ti,am62-r5f
>>>            - ti,j721s2-r5f
>>>  
>>>        reg:
>>> @@ -207,20 +216,31 @@ patternProperties:
>>>        - firmware-name
>>>  
>>>      unevaluatedProperties: false
>>
>> Blank line.
> Agreed, I will remove it in V3.
>>
>>> +allOf:
>>> +  - if:
>>> +      properties:
>>> +        compatible:
>>> +          enum:
>>> +            - ti,am64-r5fss
>>> +    then:
>>> +      properties:
>>> +        ti,cluster-mode:
>>> +          enum: [0, 2]
>>> +
>>> +    else:
>>> +      properties:
>>> +        ti,cluster-mode:
>>
>> It's not really valid anymore for ti,am62-r5fss, so this cannot be
>> simple "else".  Instead you need to list all compatibles.
> I agree that the else block is not valid for am62x, but my understanding is that since all the blocks under allOf are checked for validity,
> I thought to add a separate if block only for am62x to set cluster-mode to false [1], which I believe would negate the effect of above else condition for am62x,
> so that we don't have to list all compatibles under separate if blocks.
> 
> Just to verify this, I deliberately set cluster-mode=1 in am62x devicetree and then ran a dtbs-check and got below log : 
> "linux-next/arch/arm64/boot/dts/ti/k3-am625-sk.dtb: r5fss@...00000: ti,cluster-mode: False schema does not allow [[1]]"
> 
> and above warning log goes away when i remove the cluster-mode node in am62x devicetree.
> But please do let me know if I am missing something here or there is a better/more proper way to do this.

This was three weeks ago, so hundreds of patches ago, I don't remember
anymore.

Just look at your patch - it is clearly incorrect. You said in the patch
that for compatibles other than ti,am64-r5fss cluster mode is BOTH [0,
1] AND false.

I gave you the way to fix it. Feel free to fix it other ways if it gives
correct result.

Best regards,
Krzysztof

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