18.08.2021 07:29, Dmitry Osipenko пишет:
18.08.2021 07:12, Dmitry Osipenko пишет:
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.
Notice that we use GENPD here. GENPD core takes care of storing PD's performance state (voltage in case of Tegra) and dropping it to 0 after rpm-suspend, GENPD core also restores the state before rpm-resume.
By 'here' I mean in this series.