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From: Kalle Valo <kvalo@kernel.org>
To: Marc Gonzalez <mgonzalez@freebox.fr>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,  Konrad Dybcio
 <konrad.dybcio@linaro.org>,  Krzysztof Kozlowski
 <krzysztof.kozlowski@linaro.org>,  Jeff Johnson
 <quic_jjohnson@quicinc.com>,  ath10k <ath10k@lists.infradead.org>,
  wireless <linux-wireless@vger.kernel.org>,  DT
 <devicetree@vger.kernel.org>,  MSM <linux-arm-msm@vger.kernel.org>,  Rob
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  Pierre-Hugues Husson <phhusson@freebox.fr>,  Arnaud Vrac
 <avrac@freebox.fr>,  Bjorn Andersson <andersson@kernel.org>,  Jami
 Kettunen <jamipkettunen@gmail.com>,  Marijn Suijten
 <marijn.suijten@somainline.org>,  Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Subject: Re: [PATCH v2 3/3] arm64: dts: qcom: msm8998: set
 qcom,no-msa-ready-indicator for wifi
References: <fd26ce4a-a9f3-4ada-8d46-ed36fb2456ca@freebox.fr>
	<5cdad89c-282a-4df5-a286-b8404bc4dd81@freebox.fr>
	<252618e8-9e80-4774-a96c-caa7f838ef01@linaro.org>
	<502322f1-4f66-4922-bc4e-46bacac23410@linaro.org>
	<0ca1221b-b707-450f-877d-ca07a601624d@freebox.fr>
	<CAA8EJppeREj-0g9oGCzzKx5ywhg1mgmJR1q8yvXKN7N45do1Xg@mail.gmail.com>
	<87ttkh49xi.fsf@kernel.org>
	<e804b257-4dc0-45f1-a5c5-66bda51cf296@freebox.fr>
	<87h6gh406w.fsf@kernel.org>
	<ad5e178b-cd64-4a87-8994-f917993f3bbb@freebox.fr>
Date: Thu, 25 Apr 2024 12:42:20 +0300
In-Reply-To: <ad5e178b-cd64-4a87-8994-f917993f3bbb@freebox.fr> (Marc
	Gonzalez's message of "Mon, 8 Apr 2024 17:53:01 +0200")
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Marc Gonzalez <mgonzalez@freebox.fr> writes:

> On 04/04/2024 17:28, Kalle Valo wrote:
>
>> Marc Gonzalez wrote:
>> 
>>> On 04/04/2024 13:57, Kalle Valo wrote:
>>>
>>>> Dmitry Baryshkov wrote:
>>>>
>>>>> I'd say, we should take a step back and actually verify how this was
>>>>> handled in the vendor kernel.
>>>>
>>>> One comment related to this: usually vendor driver and firmware branches
>>>> go "hand in hand", meaning that a version of driver supports only one
>>>> specific firmware branch. And there can be a lot of branches. So even if
>>>> one branch might have a check for something specific, there are no
>>>> guarantees what the other N+1 branches do :/
>>>
>>> The consequences and ramifications of the above comment are not clear to me.
>>>
>>> Does this mean:
>>> "It is pointless to analyze a given version (or even several versions)
>>> of the vendor driver downstream, because there are exist a large number
>>> of variations of the code." ?
>> 
>> I was trying to say that because the design philosophy between vendor
>> drivers and upstream drivers is very different, we can't 100% trust
>> vendor drivers. It's a very good idea to check what vendor drivers do
>> but we just need to be careful before making any conclusions. Testing
>> real hardware (and corresponding firmware) is the most reliable way to
>> know how different products/firmware work, unfortunately.
>> 
>>> And thus, "it is nonsensical to try to "align" the mainline driver to
>>> "the" vendor driver, as there is no single "vendor driver"" ?
>> 
>> No no, I'm not saying that. I have suffered this "N+1 different firmware
>> branches behaving slighly differently" problem since ath6kl days so for
>> me this is business as usual, sadly. I'm sure we can find a solution for
>> ath10k.
>
> Hello Kalle,
>
> I can spin a v3, no problem.
>
> Do you prefer:
>
> Option A = never waiting for the MSA_READY indicator for ANYONE
> Option B = not waiting for the MSA_READY indicator when
> qcom,no-msa-ready-indicator is defined
> Option C = not waiting for the MSA_READY indicator for certain
> platforms (based on root compatible)
> Option D = some other solution not yet discussed

After firmware-N.bin solution didn't work (sorry about that!) my
prerence is option B.

> Dmitry has tested Option A on 5 platforms, where it does not induce regressions.
> I worked on msm8998, where Option A (or any equivalent) unbreaks WiFi.

What do you mean here? Are you saying that option A works on all
devices? I'm guessing I'm misunderstanding something.

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