On Mon, 29 Jul 2024 at 08:05, Viresh Kumar viresh.kumar@linaro.org wrote:
On 28-07-24, 22:05, Ulf Hansson wrote:
I think that design is rather correct, just like other frameworks. Just that we need to do only set-level for genpds and nothing else. That will have exactly the same behavior that you want.
I don't quite understand what you are proposing. Do you want to add a separate path for opp-levels?
Not separate paths, but ignore clk/regulator changes if the table belongs to a genpd.
The problem with that would be that platforms (Tegra at least) are already using a combination of opp-level and clocks.
If they are using both for a genpd's OPP table (and changes are made for both opp-level and clock by the OPP core), then it should already be wrong, isn't it?
They are changing the clock through the device's OPP table and the level (performance-state) via genpd's table (using required OPPs). This works fine as of today.
There is a problem here I guess then. Lets say there are two devices A and B, that depend on a genpd.
A requests required OPP 5 (level 5, clk 1.4 GHz), followed by B requests required OPP 3 (level 3, clk 1 GHz).
After this level will be configured to 5 and clk to 1 GHz I think.
The level would be 5, as the aggregated votes in genpd would be correct in this case.
In regards to the clocks, I assume this is handled correctly too, as the clocks are per device clocks that don't belong to the genpd.
It's working today for *opp-level* only, because of the commit above. That's correct.
Good.
My point is that calling dev_pm_opp_set_opp() recursively from _set_required_opps() doesn't make sense for the single PM domain case, as we can't assign a required-dev for it. This leads to an inconsistent behaviour when managing the required-OPPs.
We won't be calling that because of the above patch. In case of a single dev, the required device isn't set and so we will never end up calling dev_pm_opp_set_opp() for a single genpd case.
That's right, but why do we want to call dev_pm_opp_set_opp() for the multiple PM domain case then? It makes the behaviour inconsistent.
Kind regards Uffe