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Date:   Thu, 20 Apr 2023 12:20:39 +0200
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Subject: Re: [PATCH RFT v2 00/14] SMD RPMCC sleep preparations
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To:     Stephan Gerhold <stephan@gerhold.net>
Cc:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        linux-arm-msm@vger.kernel.org, linux-clk@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        devicetree@vger.kernel.org, Shawn Guo <shawn.guo@linaro.org>,
        Taniya Das <quic_tdas@quicinc.com>
References: <20230303-topic-rpmcc_sleep-v2-0-ae80a325fe94@linaro.org>
 <66c41caf-bf21-61af-c6e4-52b34b69c1ce@linaro.org>
 <ZEDwLB3RwT6mHIu4@gerhold.net>
 <6175f709-8c88-6ec3-4c31-cac9f2440b52@linaro.org>
 <ZEEOJ7VhccqCNTbj@gerhold.net>
From:   Konrad Dybcio <konrad.dybcio@linaro.org>
In-Reply-To: <ZEEOJ7VhccqCNTbj@gerhold.net>
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On 20.04.2023 12:04, Stephan Gerhold wrote:
> On Thu, Apr 20, 2023 at 11:36:24AM +0200, Konrad Dybcio wrote:
>> On 20.04.2023 09:56, Stephan Gerhold wrote:
>>> On Thu, Apr 20, 2023 at 03:50:16AM +0200, Konrad Dybcio wrote:
>>>> On 8.03.2023 22:35, Konrad Dybcio wrote:
>>>>> Keepalive clocks for other platforms were gathered by digging in old
>>>>> downstream kernels, please give them a test.
>>>> I have an implementation of rpmcc-within-icc ready(ish) locally. Turns out
>>>> some SoCs need a keepalive (19.2MHz, active-only) vote on clocks that
>>>> are NOT governed by interconnect.. So before we can disable clocks,
>>>> both will need to be implemented.. ugh... I was hoping we could avoid
>>>> having it in rpmcc..
>>> Can you give an example? Which clocks are affected on which SoC?
>> msm8998/sdm660 and PNoC
> 
> I don't see a PNoC for 8998/660, do you mean the "cnoc_periph_clk"
It's the same, but Qualcomm kept changing the name every kernel
release, so that's why we have 50 defines for the same thing
upstream :(


> downstream? Like the other NoCs it seems to be a RPM_BUS_CLK_TYPE, which
> means it does fit best into interconnect in my opinion. From a quick
> grep I don't see any usage of it in msm-4.4 downstream other than the
> active-only keepalive vote. So maybe you could just send that vote once
> in icc_rpm_smd and then ignore that clock (don't expose it at all)?
Hm, perhaps that does sound like a good idea! As far as I understand,
it's governed internally.. Older SoCs had a separate PNoC fabric
exposed.

Konrad

> 
> Thanks,
> Stephan