On 13-10-20, 14:53, Lukasz Luba wrote: > I've started wondering based on the OPP code if this is a good solution. > We would end up with one (?) instance of opp_table and list of devices > pinned to it, in: opp_table->dev_list > It can be seen e.g. in function dev_pm_opp_get_sharing_cpus(), > where we retrieve the cpumask simply looping through the devices: > > list_for_each_entry(opp_dev, &opp_table->dev_list, node) > cpumask_set_cpu(opp_dev->dev->id, cpumask); > > > This means we have a single OPP table for all pinned CPUs. > I wonder if this is not too strong assumption for still being compliant > with SCMI spec, when in theory performance levels might differ... > (please correct me here it that would never happen) > > There is also 2nd function dev_pm_opp_of_get_sharing_cpus() which looks > more promising. But I still don't know if the framework will allow us > to have private OPP tables when we use 'shared' in DT. > > Could you clarify if we would get 'private' opp table for each CPU, > which could be then populated independently, but still 2nd function will > work? I think there is some misunderstanding here in your part. The opp-table in the code is shared between CPUs only when the "opp-shared" property is present in the OPP table. If that property isn't available, even if same DT opp-table is pointed at by all the CPUs, the code will have separate copies of the OPP table. Though in your case (with performance-levels) it shouldn't matter as code will never create an OPP table I suppose. -- viresh
