Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU

From	Rob Herring <robh@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU
Date	2016-03-22 13:50 +0100
Message-ID	<rftV0-4rt-9@gated-at.bofh.it> (permalink)
References	(1 earlier) <rcNwR-4xg-1@gated-at.bofh.it> <re9vk-824-13@gated-at.bofh.it> <reFvb-39W-7@gated-at.bofh.it> <rfjCh-5JC-7@gated-at.bofh.it> <rflNL-7ws-3@gated-at.bofh.it>
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On Mon, Mar 21, 2016 at 11:00 PM, Alexandre Courbot <acourbot@nvidia.com> wrote:
> On 03/22/2016 10:41 AM, Rob Herring wrote:
>>
>> On Sun, Mar 20, 2016 at 1:55 AM, Alexandre Courbot <gnurou@gmail.com>
>> wrote:
>>>
>>> On Sat, Mar 19, 2016 at 5:47 AM, Rob Herring <robh@kernel.org> wrote:
>>>>
>>>> On Tue, Mar 15, 2016 at 11:58:42AM +0900, Alexandre Courbot wrote:
>>>>>
>>>>> GM20B's definition is mostly similar to GK20A's, but requires an
>>>>> additional clock.
>>
>>
>> [...]
>>
>>>>>        gpu@0,57000000 {
>>>>>                compatible = "nvidia,gk20a";
>>>>> @@ -45,3 +49,22 @@ Example:
>>>>>                iommus = <&mc TEGRA_SWGROUP_GPU>;
>>>>>                status = "disabled";
>>>>>        };
>>>>> +
>>>>> +Example for GM20B:
>>>>> +
>>>>> +     gpu@0,57000000 {
>>>>
>>>>
>>>> Drop the comma and leading zero.
>>>
>>>
>>> Even though this is how it appears in the actual DT?
>>
>>
>> Yes, those will need to get fixed, too.
>
>
> Sorry, I just want to confirm that I understand why this needs to be fixed.
> The parent node has #address-cells = <2>, and the practice of specifying two
> cells in the node name is consistent with what I see in
> http://www.devicetree.org/Device_Tree_Usage.
>
> However in the device tree usage example one can interpret the two cells as
> being two different components of the address, whereas in our case we are
> using two cells because the address is 64-bit - hence we should specify it
> in the name as a single entity. Is this correct?

Exactly, commas are for separating distinct fields like chip select
and offset in the wiki example. A 64-bit address is a single field.

The other reason to fix it is dtc is going to start warning for this.

Rob

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Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU Rob Herring <robh@kernel.org> - 2016-03-18 21:50 +0100
  Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU Alexandre Courbot <gnurou@gmail.com> - 2016-03-20 08:00 +0100
    Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU Rob Herring <robh@kernel.org> - 2016-03-22 02:50 +0100
      Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU Alexandre Courbot <acourbot@nvidia.com> - 2016-03-22 05:10 +0100
        Re: [PATCH v2 3/5] dt-bindings: Add documentation for GM20B GPU Rob Herring <robh@kernel.org> - 2016-03-22 13:50 +0100

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