On 2/8/2019 1:17 AM, Stephen Boyd wrote:
Quoting Rajendra Nayak (2019-02-06 22:57:12)
3) How do we handle devices that already have power-domains specified in
DT? The opp binding for required-opps doesn't let us specify the power
domain to target, instead it assumes that whatever power domain is
attached to a device is the one that OPP needs to use to change the
genpd performance state. Do we need a
dev_pm_opp_set_required_opps_name() or something to be explicit about
this? Can we have some way for the power domain that required-opps
correspond to be expressed in the OPP tables themselves?
I was converting a few more drivers to use the proposed approach in this
RFC, in order to identify all outstanding issues we need to deal with,
and specifically for UFS, I end up with this exact scenario where UFS already
has an existing power domain (gdsc) and I need to add another one (rpmhpd) for
setting the performance state.
If I use dev_pm_opp_of_add_table() to add the opp table from DT, the opp
layer assumes its the same device on which it can do a dev_pm_genpd_set_performance_state()
with, however the device that's actually associated with the pm_domain when we
have multiple power domains is infact the one (dummy) that we create when
the driver makes a call to dev_pm_domain_attach_by_name/id().
Any thoughts on whats a good way to handle this?
Ulf mentioned that we can use dev_pm_opp_set_genpd_virt_dev() for this.
Does that API work here?
Ah, yes, that should work, I hadn't noticed this API existed.
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