Re: [PATCH] arm64: dts: ls1012a: add crypto node

["Horia Geantă" <horia.geanta@nxp.com>]

On 3/24/2017 4:04 PM, Shawn Guo wrote:
> On Fri, Mar 24, 2017 at 08:29:17AM +0000, Horia Geantă wrote:
>> On 3/24/2017 9:35 AM, Shawn Guo wrote:
>>> On Fri, Mar 24, 2017 at 07:17:50AM +0000, Horia Geantă wrote:
>>>>>> +		sec_mon: sec_mon@1e90000 {
>>>>>
>>>>> Hyphen is more preferred to be used in node name than underscore.
>>>>>
>>>> This would imply changing the
>>>> Documentation/devicetree/bindings/crypto/fsl-sec4.txt binding and
>>>> dealing with all the consequences, which IIUC is probably not worth.
>>>
>>> I do not care the bindings doc that much, since I'm not the maintainer
>>> of it.  What are the consequences specifically, if we use a better node
>>> name in dts than bindings example?
>>>
>> Users relying on finding the sec_mon node will obviously stop working.
>> I don't see any in-kernel users, however there could be others I am not
>> aware of and DT bindings should provide for backwards compatibility.
> 
> Okay, point taken.  You can keep the node name as it is.
> 
>> I could deprecate "sec_mon" in the bindings and suggest "sec-mon"
>> instead, while leaving all existing dts files as-is.
>> The risk is breaking LS1012A users relying on "sec_mon".
> 
> For existing bindings, I do not care that much.  But for new ones, I do
> hope that we recommend to use hyphen, as that's more idiomatic at least
> for Linux kernel.
> 
>> I see that ePAPR:
>> -allows both for hyphen and underline in case of node names
>> -allows only for hyphen (i.e. forbids underline) in case of alias nodes
>>
>> In the first case, I understand there's an (undocumented?) agreement to
>> prefer hyphen over underline.
> 
> Both are valid, but hyphen is more idiomatic for Linux kernel.
> 
>> For the 2nd one, does this mean I should change alias names?
> 
> This is something I see difference between specification and DTC.
> 
> 	aliases {
> 		alias-name = &label_name;
> 	};
> 
> 	label_name: node-name {
> 		...
> 	};
> 
> The spec says that only hyphen is valid for alias name, but DTC works
> happily with underscore too.  From my experience with DTC playing, both
> hyphen and underscore are valid for alias and node name.  But for label
> name, only underscore is valid.  Using hyphen in label name will cause
> DTC to report syntax error.
> 
Yes indeed, thanks for pointing it out.

For the sake of current patch, please clarify whether a v2 is needed.
IIUC:
-sec_mon node name could stay the same (existing binding)
-label names are ok, since underline is the only option allowed by DTC
-alias names are out-of-spec but accepted by DTC; if changing underline
to hyphen is requested, I will push out v2

Thanks,
Horia