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Date: Fri, 26 Jan 2024 10:15:54 +0100
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Subject: Re: [PATCH v2 1/2] dt-bindings: usb: mt6360-tcpc: Drop
 interrupt-names
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To: Conor Dooley <conor@kernel.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>, robh+dt@kernel.org,
 krzysztof.kozlowski+dt@linaro.org, chunfeng.yun@mediatek.com,
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References: <20240119094105.98312-1-angelogioacchino.delregno@collabora.com>
 <20240119-eldest-discharge-e2d3812be0a9@spud>
 <12b7b339-498b-45c1-bc5e-05e07660aefa@collabora.com>
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 <abbc1135-6d32-421a-baea-123a9f761362@collabora.com>
 <20240125-disdain-delivery-ff3bf246bbe1@spud>
 <20240125-elective-sermon-32dc2cba79be@spud>
From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
In-Reply-To: <20240125-elective-sermon-32dc2cba79be@spud>
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Il 25/01/24 18:02, Conor Dooley ha scritto:
> On Thu, Jan 25, 2024 at 04:57:33PM +0000, Conor Dooley wrote:
>> On Thu, Jan 25, 2024 at 12:41:57PM +0100, AngeloGioacchino Del Regno wrote:
>>> Il 25/01/24 11:32, Krzysztof Kozlowski ha scritto:
>>>> On 24/01/2024 09:48, AngeloGioacchino Del Regno wrote:
>>>>> Il 23/01/24 18:14, Conor Dooley ha scritto:
>>>>>> On Mon, Jan 22, 2024 at 11:32:30AM +0100, AngeloGioacchino Del Regno wrote:
>>>>>>> Il 19/01/24 17:32, Conor Dooley ha scritto:
>>>>>>>> On Fri, Jan 19, 2024 at 10:41:04AM +0100, AngeloGioacchino Del Regno wrote:
>>>>>>>>> This IP has only one interrupt, hence interrupt-names is not necessary
>>>>>>>>> to have.
>>>>>>>>> Since there is no user yet, simply remove interrupt-names.
>>>>>>>>
>>>>>>>> I'm a bit confused chief. Patch 2 in this series removes a user of this
>>>>>>>> property from a driver, so can you explain how this statement is true?
>>>>>>>>
>>>>>>>> Maybe I need to drink a few cans of Monster and revisit this patchset?
>>>>>>>>
>>>>>>>
>>>>>>> What I mean with "there is no user" is that there's no device tree with any
>>>>>>> mt6360-tcpc node upstream yet, so there is no meaningful ABI breakage.
>>>>>>> Different story would be if there was a device tree using this already, in
>>>>>>> which case, you can make a required property optional but not remove it.
>>>>>>
>>>>>> Not every devicetree lives within the kernel.. If the driver is using
>>>>>> it, I'm not inclined to agree that it should be removed.
>>>>>
>>>>> I get the point, but as far as I remember, it's not the first time that this
>>>>> kind of change is upstreamed.
>>>>>
>>>>> I'm fine with keeping things as they are but, since my intention is to actually
>>>>> introduce an actual user of this binding upstream, and that actually depends on
>>>>> if this change is accepted or not (as I have to know whether I can omit adding
>>>>> the interrupt-names property or not)....
>>>>>
>>>>> ....may I ask for more feedback/opinions from Rob and/or Krzk?
>>>>
>>>> Driver is the user and this is an old binding (released!), thus there
>>>> can be out-of-kernel users already.
>>>>
>>>> Minor cleanup is not really a reason to affect ABI. You could deprecate
>>>> it, though. Driver change is fine.
>>>>
>>>
>>> Thanks for the clarification. If USB maintainers want to take the driver part only
>>> without me resending this, I'd appreciate that.
>>>
>>
>>> The interrupt-names is not a required property in this binding anyway... :-)
>>
>> Having -names properties that are not required when the base property is
>> always seem so pointless to me, except in cases where they're not
>> required for the case where there's one item but required when there are
>> more than one. Ultimately they're pointless if not required since they
>> can't be relied on. I think dropping it from the driver is required for
>> correctness.
> 
> Actually, looking at the binding again:
> 
> | required:
> |   - compatible
> |   - interrupts
> |   - interrupt-names
> 
> It looks like it is a required property after all!

Apparently my brain's binding had

required:
   - blindness

:-P

Yeah, I have no idea why I didn't see that, sorry!

Cheers,
Angelo