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Date:   Wed, 30 Nov 2022 20:41:14 +0530
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Subject: Re: [PATCH 1/3] dt-bindings: PHY: P2U: Add PCIe lane margining
 support
Content-Language: en-US
To:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        vkoul@kernel.org, kishon@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, thierry.reding@gmail.com,
        jonathanh@nvidia.com, vidyas@nvidia.com
Cc:     linux-phy@lists.infradead.org, devicetree@vger.kernel.org,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-pci@vger.kernel.org, bhelgaas@google.com,
        lpieralisi@kernel.org, nkristam@nvidia.com
References: <20221124083510.3008139-1-mmaddireddy@nvidia.com>
 <20221124083510.3008139-2-mmaddireddy@nvidia.com>
 <0b203c11-851c-fd6c-faeb-e283b158f1c8@linaro.org>
From:   Manikanta Maddireddy <mmaddireddy@nvidia.com>
In-Reply-To: <0b203c11-851c-fd6c-faeb-e283b158f1c8@linaro.org>
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Thank you for quick review. I will wait for other reviewers to review 
patch 2 & 3.
I will address all review comments and sendnew revision.

On 11/24/2022 2:15 PM, Krzysztof Kozlowski wrote:
> External email: Use caution opening links or attachments
>
>
> On 24/11/2022 09:35, Manikanta Maddireddy wrote:
>> Tegra234 supports PCIe lane margining. P2U HW acts as a relay to exchange
> typo: merging?
It is not typo, it is PCIe feature lane margining.
https://pcisig.com/pushing-limits-understanding-lane-margining-pcie%C2%AE
>
>> margin control data and margin status between PCIe controller and UPHY.
> Please use scripts/get_maintainers.pl to get a list of necessary people
> and lists to CC.  It might happen, that command when run on an older
> kernel, gives you outdated entries.  Therefore please be sure you base
> your patches on recent Linux kernel.
I verified these patches on 6.0.0-rc6 kernel and executed get_maintainers.pl
script on it. Did I miss anyone here?
>
>
>> Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
>> ---
>>   .../bindings/phy/phy-tegra194-p2u.yaml        | 50 +++++++++++++++++++
>>   1 file changed, 50 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/phy/phy-tegra194-p2u.yaml b/Documentation/devicetree/bindings/phy/phy-tegra194-p2u.yaml
>> index 4dc5205d893b..0ba3f6a0b474 100644
>> --- a/Documentation/devicetree/bindings/phy/phy-tegra194-p2u.yaml
>> +++ b/Documentation/devicetree/bindings/phy/phy-tegra194-p2u.yaml
>> @@ -40,6 +40,51 @@ properties:
>>     '#phy-cells':
>>       const: 0
>>
>> +  interrupts:
>> +    items:
>> +      description: P2U interrupt for Gen4 lane margining functionality.
> typo: merging?
It is not typo, it is PCIe feature lane margining.
https://pcisig.com/pushing-limits-understanding-lane-margining-pcie%C2%AE
>
>> +
>> +  interrupt-names:
>> +    items:
>> +      - const: intr
> Drop entire property, not really useful.
In driver, I am using platform_get_irq_byname(), I will change it to 
platform_get_irq()
and drop this property.
>
>> +
>> +  nvidia,bpmp:
>> +    $ref: /schemas/types.yaml#/definitions/phandle-array
>> +    description: Must contain a pair of phandles to BPMP controller node followed by P2U ID.
>> +    items:
>> +      - items:
>> +          - description: phandle to BPMP controller node
>> +          - description: P2U instance ID
>> +            maximum: 24
>> +
>> +allOf:
>> +  - if:
>> +      properties:
>> +        compatible:
>> +          contains:
>> +            enum:
>> +              - nvidia,tegra194-p2u
>> +    then:
>> +      required:
>> +        - reg
>> +        - reg-names
>> +        - '#phy-cells'
> That's not how it should be done. You have only two variants here, so
> add a "required:" block with above and only one if:then: clause for
> interrupts and nvidia,bpmp.
>
> Requiring reg/reg-names/phy-cells should be in separate patch with its
> own reasoning.
Ok, I will create two separate patches and add if:then clause only for 
tegra234.
As per understanding final change will look like below, right?


required:
   - reg
   - reg-names
   - '#phy-cells'

allOf:
   - if:
       properties:
         compatible:
           contains:
             enum:
               - nvidia,tegra234-p2u
     then:
       required:
         - interrupts
         - nvidia,bpmp

>
>
> Best regards,
> Krzysztof
>