linux-kernel - Re: [PATCH V2 00/13] OPP: Add support for multiple clocks*

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Date:   Mon, 11 Jul 2022 18:40:50 +0200
From:   Johan Hovold <johan@...nel.org>
To:     Viresh Kumar <viresh.kumar@...aro.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>
Cc:     Chanwoo Choi <cw00.choi@...sung.com>,
        Dmitry Osipenko <digetx@...il.com>,
        Jonathan Hunter <jonathanh@...dia.com>,
        Kyungmin Park <kyungmin.park@...sung.com>,
        MyungJoo Ham <myungjoo.ham@...sung.com>,
        Nishanth Menon <nm@...com>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Stephen Boyd <sboyd@...nel.org>,
        Thierry Reding <thierry.reding@...il.com>,
        Viresh Kumar <vireshk@...nel.org>, linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        devicetree@...r.kernel.org,
        Dmitry Osipenko <dmitry.osipenko@...labora.com>,
        linux-kernel@...r.kernel.org, linux-tegra@...r.kernel.org,
        Manivannan Sadhasivam <manivannan.sadhasivam@...aro.org>,
        Rob Herring <robh@...nel.org>
Subject: Re: [PATCH V2 00/13] OPP: Add support for multiple clocks*

On Tue, Jul 05, 2022 at 12:30:03PM +0530, Viresh Kumar wrote:
> Hello,
> 
> This patchset adds support for devices with multiple clocks. None of the clocks
> is considered primary in this case and all are handled equally.
> 
> The drivers, for multiple clock case, are expected to call dev_pm_opp_set_opp()
> to set the specific OPP. Though how they find the target OPP is left for the
> users to handle. For some, we may have another unique OPP property, like level,
> which can be used to find the OPP. While in case of others, we may want to
> implement freq-based OPP finder APIs for multiple clock rates. I have decided
> not to implement them in advance, and add them only someone wants to use them.

This break OPP parsing on SC8280XP and hence cpufreq and other things:

[  +0.010890] cpu cpu0: _opp_add_static_v2: opp key field not found
[  +0.000019] cpu cpu0: _of_add_opp_table_v2: Failed to add OPP, -19
[  +0.000060] cpu cpu0: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 300000000, volt: 576000, enabled: 1. New: freq: 403200000, volt: 576000, enabled: 1
[  +0.000030] cpu cpu0: _opp_is_duplicate: duplicate OPPs detected. Existing: freq: 300000000, volt: 576000, enabled: 1. New: freq: 499200000, volt: 576000, enabled: 1
...

I just did a rebase on next-20220708 and hit this.

I've narrowed it down to _read_rate() now returning -ENODEV since
opp_table->clk_count is zero.

Similar to what was reported for tegra for v1:

	https://lore.kernel.org/all/58cc8e3c-74d4-e432-8502-299312a1f15e@collabora.com/

I don't have time to look at this any more today, but it would we nice
if you could unbreak linux-next.

Perhaps Bjorn or Mani can help with further details, but this doesn't
look like something that is specific to SC8280XP.

Johan