linux-kernel - Re: [PATCH 2/2] OPP: Disallow "opp-hz" property without a corresponding clk

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Message-ID: <20231011054858.3vvnr76u5enu5lf6@vireshk-i7>
Date:   Wed, 11 Oct 2023 11:18:58 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Cc:     Johan Hovold <johan@...nel.org>, Viresh Kumar <vireshk@...nel.org>,
        Nishanth Menon <nm@...com>, Stephen Boyd <sboyd@...nel.org>,
        linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>, andersson@...nel.org,
        krzysztof.kozlowski+dt@...aro.org, linux-kernel@...r.kernel.org,
        robdclark@...il.com
Subject: Re: [PATCH 2/2] OPP: Disallow "opp-hz" property without a
 corresponding clk

On 16-02-23, 12:17, Manivannan Sadhasivam wrote:
> Sorry for the delay. I've submitted the dts changes [1] to handle the CPU clocks
> for the rest of the Qcom SoCs.
> 
> For the Qcom GPUs, I've CCed Rob Clark who is the maintainer.
> 
> Rob, here is the background on the issue that is being discussed in this
> thread:
> 
> Viresh submitted a series [2] back in July to improve the OPP framework, but
> that ended up breaking cpufreq on multiple Qcom SoCs. After investigation, it
> was found that the series was expecting the clocks supplied to the OPP end
> devices like CPUs/GPUs to be modeled in DT. But on Qcom platforms even though
> the clocks for these nodes are supplied by a separate entity, like CPUFreq
> (EPSS/OSM) for CPUs and GMU for GPUs, there was no clock property present in
> the respective nodes. And these nodes are using OPP table to switch frequencies
> dynamically.
> 
> While the series was merged with a hack that still allows the OPP nodes without
> clock property in DT, we came to an agreement that the clock hierarchy should
> be modeled properly.
> 
> So I submitted a series [3] that added clock provider support to cpufreq driver
> and sourced the clock from cpufreq node to CPU nodes in DT.
> 
> Likewise, it should be handled for the adreno GPUs whose clock is managed by
> GMU on newer SoCs. Can you take a look at this?

Any update on this ?

-- 
viresh