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Date:   Wed, 29 Nov 2023 16:20:16 +0530
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Subject: Re: [PATCH 1/6] dt-bindings: usb: dwc3: Clean up hs_phy_irq in
 bindings
To:     Johan Hovold <johan@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.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>
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From:   Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
In-Reply-To: <ZWcPZPX-eT-xHAOv@hovoldconsulting.com>
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On 11/29/2023 3:46 PM, Johan Hovold wrote:
> On Wed, Nov 29, 2023 at 10:28:25AM +0100, Krzysztof Kozlowski wrote:
>> On 28/11/2023 12:32, Krishna Kurapati PSSNV wrote:
>>>
>>>>
>>>> So back to my initial proposal, with a slight modification moving
>>>> pwr_event first (e.g. as it is not a wakeup interrupt):
>>>>
>>>> qusb2-:
>>>>
>>>> 	- const: pwr_event
>>>> 	- const: qusb2_phy
>>>> 	- const: ss_phy_irq	(optional)
>>>>
>>>> qusb2:
>>>>
>>>> 	- const: pwr_event
>>>> 	- const: hs_phy_irq
>>>> 	- const: qusb2_phy
>>>> 	- const: ss_phy_irq	(optional)
>>>>
>>>> femto-:
>>>> 	- const: pwr_event
>>>> 	- const: dp_hs_phy_irq
>>>> 	- const: dm_hs_phy_irq
>>>> 	- const: ss_phy_irq	(optional)
>>>>
>>>> femto:
>>>> 	- const: pwr_event
>>>> 	- const: hs_phy_irq
>>>> 	- const: dp_hs_phy_irq
>>>> 	- const: dm_hs_phy_irq
>>>> 	- const: ss_phy_irq	(optional)
>>
>> I did not follow entire thread and I do not know whether you change the
>> order in existing bindings, but just in case: the entries in existing
>> bindings cannot change the order. That's a strict ABI requirement
>> recently also discussed with Bjorn, because we want to have stable DTB
>> for laptop platforms. If my comment is not relevant, then please ignore.
> 
> Your comment is relevant, but I'm not sure I agree.
> 
> The Qualcomm bindings are a complete mess of DT snippets copied from
> vendor trees and which have not been sanitised properly before being
> merged upstream (partly due to there not being any public documentation
> available).
> 
> This amounts to an unmaintainable mess which is reflected in the
> binding schemas which similarly needs to encode every random order which
> the SoC happened to use when being upstreamed. That makes the binding
> documentation unreadable too, and the next time a new SoC is upstreamed
> there is no clear hints of what the binding should look like, and we end
> up with yet another permutation.
> 
> As part of this exercise, we've also determined that some of the
> devicetrees that are already upstream are incorrect as well as
> incomplete.
> 
> I really see no alternative to ripping of the plaster and cleaning this
> up once and for all even if it "breaks" some imaginary OS which (unlike
> Linux) relies on the current random order of these interrupts.
> 
> [ If there were any real OSes actually relying on the order, then that
> would be a different thing of course. ]
> 

Hi Krzysztof, Johan,

   We are modifying all the DT's in accordance to bindings as well. 
Still it would be breaking ABI ?

Regards,
Krishna,