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    SubjectRe: [PATCH v8 01/34] opp: Add dev_pm_opp_sync() helper
    On 18-08-21, 07:12, Dmitry Osipenko wrote:
    > 18.08.2021 06:55, Viresh Kumar пишет:
    > > On 17-08-21, 18:49, Dmitry Osipenko wrote:
    > >> 17.08.2021 10:55, Viresh Kumar пишет:
    > >> ...
    > >>>> +int dev_pm_opp_sync(struct device *dev)
    > >>>> +{
    > >>>> + struct opp_table *opp_table;
    > >>>> + struct dev_pm_opp *opp;
    > >>>> + int ret = 0;
    > >>>> +
    > >>>> + /* Device may not have OPP table */
    > >>>> + opp_table = _find_opp_table(dev);
    > >>>> + if (IS_ERR(opp_table))
    > >>>> + return 0;
    > >>>> +
    > >>>> + if (!_get_opp_count(opp_table))
    > >>>> + goto put_table;
    > >>>> +
    > >>>> + opp = _find_current_opp(dev, opp_table);
    > >>>> + ret = _set_opp(dev, opp_table, opp, opp->rate);
    > >>>
    > >>> And I am not sure how this will end up working, since new OPP will be
    > >>> equal to old one. Since I see you call this from resume() at many
    > >>> places.
    > >>
    > >> Initially OPP table is "uninitialized" and opp_table->enabled=false,
    > >> hence the first sync always works even if OPP is equal to old one. Once
    > >> OPP has been synced, all further syncs are NO-OPs, hence it doesn't
    > >> matter how many times syncing is called.
    > >>
    > >> https://elixir.bootlin.com/linux/v5.14-rc6/source/drivers/opp/core.c#L1012
    > >
    > > Right, but how will this work from Resume ? Won't that be a no-op ?
    >
    > The first resume initializes the OPP state on sync, all further syncs on
    > resume are no-ops.

    But the OPPs should already be initialized as someone must have called
    opp-set-rate earlier ? Why do this from resume and not probe ?

    --
    viresh

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