Re: [PATCH] dt/documentation: add specification of dma bus information

[Santosh Shilimkar]

On Friday 20 June 2014 03:46 PM, Rob Herring wrote:
> On Fri, Jun 20, 2014 at 2:02 PM, Santosh Shilimkar
> <santosh.shilimkar@xxxxxx> wrote:
>> On Friday 20 June 2014 02:56 PM, Arnd Bergmann wrote:
>>> On Friday 20 June 2014 13:17:43 Santosh Shilimkar wrote:
>>>>>> +                       dma-coherent;
>>>>>> +                       dma-ranges;
>>>>>> +
>>>>>> +                       dwc3@2690000 {
>>>>>> +                               compatible = "synopsys,dwc3";
>>>>>> +                               [...]
>>>>>> +                       };
>>>>>
>>>>> This example is a bit strange. I don't understand the relationship
>>>>> between keystone-dwc3 and synopsys,dwc3, nor do I want to. I'd prefer
>>>>> to see a simple example here.
>>>
>>>
>>>>> dma-ranges is a property of the parent which you show, but
>>>>> dma-coherent originally was a property of the bus master itself. While
>>>>> we need to support that, are we changing that? We need to be clear on
>>>>> where the property belongs even if the kernel is more lax.
>>>>>
>>>> I don't think we are changing it fundamentally but may be I missing
>>>> your point. The dma-coherent as is now a per-device property.
>>>> USB is one of the bus master supports coherency and hence showed
>>>> up in above example.
>>>
>>> I think it's enough if you just drop the "synopsys,dwc3" node and the
>>> intermediate dma-ranges property from the example, leaving the
>>> dma-coherent property in the "ti,keystone-dwc3" node.
>>>
>> Thanks Arnd. That should avoid the confusion. Just to see if Rob is
>> fine by it, the example will look like below.
> 
> Yes. Looks fine.
> 
Great. Updated version 2 below.