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Subject: Re: [PATCH 1/4] dt-bingings: PCI: Remove the num-lanes from Required
 properties
To:     "Z.q. Hou" <zhiqiang.hou@nxp.com>,
        Andrew Murray <andrew.murray@arm.com>
CC:     "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "gustavo.pimentel@synopsys.com" <gustavo.pimentel@synopsys.com>,
        "jingoohan1@gmail.com" <jingoohan1@gmail.com>,
        "bhelgaas@google.com" <bhelgaas@google.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "mark.rutland@arm.com" <mark.rutland@arm.com>,
        "shawnguo@kernel.org" <shawnguo@kernel.org>,
        Leo Li <leoyang.li@nxp.com>,
        "lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
        "M.h. Lian" <minghuan.lian@nxp.com>,
        Gabriele Paoloni <gabriele.paoloni@huawei.com>
References: <20190812042435.25102-1-Zhiqiang.Hou@nxp.com>
 <20190812042435.25102-2-Zhiqiang.Hou@nxp.com>
 <20190812084517.GW56241@e119886-lin.cambridge.arm.com>
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From:   Kishon Vijay Abraham I <kishon@ti.com>
Message-ID: <286ea8d2-5467-6cc2-07cb-7707db13ad1a@ti.com>
Date:   Tue, 13 Aug 2019 10:05:42 +0530
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Hi,

On 13/08/19 8:37 AM, Z.q. Hou wrote:
> Hi Andrew,
> 
> Thanks a lot for your comments!
> 
>> -----Original Message-----
>> From: Andrew Murray <andrew.murray@arm.com>
>> Sent: 2019??8??12?? 16:45
>> To: Z.q. Hou <zhiqiang.hou@nxp.com>
>> Cc: linux-pci@vger.kernel.org; devicetree@vger.kernel.org;
>> linux-kernel@vger.kernel.org; gustavo.pimentel@synopsys.com;
>> jingoohan1@gmail.com; bhelgaas@google.com; robh+dt@kernel.org;
>> mark.rutland@arm.com; shawnguo@kernel.org; Leo Li
>> <leoyang.li@nxp.com>; lorenzo.pieralisi@arm.com; M.h. Lian
>> <minghuan.lian@nxp.com>; Kishon Vijay Abraham I <kishon@ti.com>;
>> Gabriele Paoloni <gabriele.paoloni@huawei.com>
>> Subject: Re: [PATCH 1/4] dt-bingings: PCI: Remove the num-lanes from
>> Required properties
>>
>> On Mon, Aug 12, 2019 at 04:22:16AM +0000, Z.q. Hou wrote:
>>> From: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
>>>
>>> The num-lanes is not a mandatory property, e.g. on FSL Layerscape
>>> SoCs, the PCIe link training is completed automatically base on the
>>> selected SerDes protocol, it doesn't need the num-lanes to set-up the
>>> link width.
>>>
>>> It has been added in the Optional properties. This patch is to remove
>>> it from the Required properties.
>>
>> For clarity, maybe this paragraph can be reworded to:
>>
>> "It is previously in both Required and Optional properties,  let's remove it
>> from the Required properties".
> 
> Agree and will change in v2.
> 
>>
>> I don't understand why this property is previously in both required and
>> optional...
>>
>> It looks like num-lanes was first made optional back in
>> 2015 and removed from the Required section (907fce090253).
>> But then re-added back into the Required section in 2017 with the adition of
>> bindings for EP mode (b12befecd7de).
>>
>> Is num-lanes actually required for EP mode?
> 
> Kishon, please help to answer this query?

It should be optional for EP too.

Thanks
Kishon