Re: [PATCH 3/6] doc: dt: Document the indirect overlay method.

From: Rob Herring
Date: Tue May 10 2016 - 10:37:14 EST


On Tue, May 10, 2016 at 8:59 AM, Pantelis Antoniou
<pantelis.antoniou@xxxxxxxxxxxx> wrote:
> Hi Rob,
>
>> On May 10, 2016, at 00:59 , Rob Herring <robherring2@xxxxxxxxx> wrote:
>>
>> On Mon, May 9, 2016 at 1:05 PM, Pantelis Antoniou
>> <pantelis.antoniou@xxxxxxxxxxxx> wrote:
>>> Add a description of the indirect overlay method to the overlay
>>> documention file.
>>
>> Why? Please write some decent commit messages.
>>
>>> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
>>> ---
>>> Documentation/devicetree/overlay-notes.txt | 13 +++++++++++++
>>> 1 file changed, 13 insertions(+)
>>>
>>> diff --git a/Documentation/devicetree/overlay-notes.txt b/Documentation/devicetree/overlay-notes.txt
>>> index d418a6c..dd595e6 100644
>>> --- a/Documentation/devicetree/overlay-notes.txt
>>> +++ b/Documentation/devicetree/overlay-notes.txt
>>> @@ -100,6 +100,10 @@ Finally, if you need to remove all overlays in one-go, just call
>>> of_overlay_destroy_all() which will remove every single one in the correct
>>> order.
>>>
>>> +If your board has multiple slots/places where a single overlay can work
>>> +and each slot is defined by a node, you can use the of_overlay_create_indirect()
>>> +method to select the target.
>>> +
>>> Overlay DTS Format
>>> ------------------
>>>
>>> @@ -113,6 +117,11 @@ The DTS of an overlay should have the following format:
>>> target=<phandle>; /* phandle target of the overlay */
>>> or
>>> target-path="/path"; /* target path of the overlay */
>>
>> Why not just let these take multiple values and the user just selects index?
>>
>
> Implementation details. Usually thereâs a descriptive label used for each
> different target point. It could be a slot# or it could be a labelâ
>
> A string selector maps better IMO.

Then add "target-names" perhaps.

What I really don't like is 3 different ways to specify the target and
having to maintain them (I'm not sure why we allowed 2 to start
with.). Come up with a single way that works for 1 or more targets. If
that is different than the current way, then let's deprecate the old
way.

Rob