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

Rob Herring robherring2 at gmail.com
Fri Sep 26 09:32:25 PDT 2014


On Fri, Sep 19, 2014 at 1:29 PM, Grygorii Strashko
<grygorii.strashko at ti.com> wrote:
> Hi Rob,
>
>
> On 06/22/2014 10:40 PM, Santosh Shilimkar wrote:
>>
>> On Friday 20 June 2014 03:46 PM, Rob Herring wrote:
>>>
>>> On Fri, Jun 20, 2014 at 2:02 PM, Santosh Shilimkar
>>> <santosh.shilimkar at ti.com> 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 at 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.
>
>
> Seems, this patch has not been merged accidentally :(
> Is it possible for you to take it, or would you like me to re-send it?

Applied. Sorry for the delay.

Rob



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