[1/4] dt-bingings: PCI: Remove the num-lanes from Required properties
diff mbox series

Message ID 20190812042435.25102-2-Zhiqiang.Hou@nxp.com
State New
Headers show
Series
  • Layerscape: Remove num-lanes property from PCIe nodes
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Commit Message

Z.q. Hou Aug. 12, 2019, 4:22 a.m. UTC
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.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
---
 Documentation/devicetree/bindings/pci/designware-pcie.txt | 1 -
 1 file changed, 1 deletion(-)

Comments

Andrew Murray Aug. 12, 2019, 8:45 a.m. UTC | #1
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".

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?

Thanks,

Andrew Murray

> 
> Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> ---
>  Documentation/devicetree/bindings/pci/designware-pcie.txt | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
> index 5561a1c060d0..bd880df39a79 100644
> --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
> +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
> @@ -11,7 +11,6 @@ Required properties:
>  	     the ATU address space.
>      (The old way of getting the configuration address space from "ranges"
>      is deprecated and should be avoided.)
> -- num-lanes: number of lanes to use
>  RC mode:
>  - #address-cells: set to <3>
>  - #size-cells: set to <2>
> -- 
> 2.17.1
>
Z.q. Hou Aug. 13, 2019, 3:07 a.m. UTC | #2
Hi Andrew,

Thanks a lot for your comments!

> -----Original Message-----
> From: Andrew Murray <andrew.murray@arm.com>
> Sent: 2019年8月12日 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?

Thanks,
Zhiqiang

> 
> Thanks,
> 
> Andrew Murray
> 
> >
> > Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
> > ---
> >  Documentation/devicetree/bindings/pci/designware-pcie.txt | 1 -
> >  1 file changed, 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt
> > b/Documentation/devicetree/bindings/pci/designware-pcie.txt
> > index 5561a1c060d0..bd880df39a79 100644
> > --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
> > +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
> > @@ -11,7 +11,6 @@ Required properties:
> >  	     the ATU address space.
> >      (The old way of getting the configuration address space from
> "ranges"
> >      is deprecated and should be avoided.)
> > -- num-lanes: number of lanes to use
> >  RC mode:
> >  - #address-cells: set to <3>
> >  - #size-cells: set to <2>
> > --
> > 2.17.1
> >
Kishon Vijay Abraham I Aug. 13, 2019, 4:35 a.m. UTC | #3
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年8月12日 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

Patch
diff mbox series

diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
index 5561a1c060d0..bd880df39a79 100644
--- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
+++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
@@ -11,7 +11,6 @@  Required properties:
 	     the ATU address space.
     (The old way of getting the configuration address space from "ranges"
     is deprecated and should be avoided.)
-- num-lanes: number of lanes to use
 RC mode:
 - #address-cells: set to <3>
 - #size-cells: set to <2>