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Date:   Tue, 28 Nov 2023 16:02:53 +0530
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Subject: Re: [PATCH 1/6] dt-bindings: usb: dwc3: Clean up hs_phy_irq in
 bindings
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To:     Johan Hovold <johan@kernel.org>
CC:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        "Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>, <quic_wcheng@quicinc.com>,
        <linux-arm-msm@vger.kernel.org>, <linux-usb@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <quic_ppratap@quicinc.com>, <quic_jackp@quicinc.com>
References: <20231122191335.3058-1-quic_kriskura@quicinc.com>
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From:   Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
In-Reply-To: <ZWW_FOAKp95Cf9vN@hovoldconsulting.com>
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>>>>> Now if the HS interrupt is truly unusable, I guess we can consider
>>>>> dropping it throughout and the above becomes just three permutations
>>>>> instead, which can even be expressed along the lines of:
>>>>
>>>> Infact, I wanted to do this but since you mentioned before that if HW
>>>> has it, we must describe it, I kept it in. But since this functionality
>>>> is confirmed to be mutually exclusive of qusb2/{dp/dm}, I am aligned to
>>>> skip it in bindings and drop it in DT.
>>>
>>> As I mentioned elsewhere, it depends on whether it can be used at all.
>>> Not simply whether there is some other mechanism that can be used in its
>>> stead. Such a decision should be left up to the implementation.
>>>
>>> That's why I said "truly unusable" above. It's still not clear to me
>>> whether that is the case or not.
>>
>> I looked at the code of  4.4, 4.14/ 4.19/ 5.4/ 5.10/ 5.15/ 6.1 and none
>> of them implement the hs_phy_irq.
> 
> But again, that is completely irrelevant. As I've said numerous times
> now, this is about what the hardware is capable of, not which
> functionality a particular OS chooses to use.
>    >> My opinion would be to keep the power_event irq as mandatory and not to
>> include the hs_phy_irq.
> 
> Ok, but you still need to explain why dropping hs_phy_irq is correct.
> 
> Until there's a clear answer to that, it seems we need to include it.

Sure, I agree with you. It should describe what hardware is capable of, 
not what we choose to add in driver code. In that sense we can add the 
hs_phy_irq to all targets.

In my next revision, I can do the following:

	- anyOf:
	  - items:
	    - const: qusb2_phy
	  - items:
	    - const: dp_hs_phy_irq
	    - const: dm_hs_phy_irq
	- const: hs_phy_irq
	- const: pwr_event
	- const: ss_phy_irq	(optional)

A modified version of your suggestion should help cover all cases and 
describe all DT's perfectly.

Let me know your thoughts on this.

Regards,
Krishna,