On Sat, Jun 09, 2012 at 12:39:15PM -0700, Philip Rakity wrote: > - trace_regulator_set_voltage_complete(rdev_get_name(rdev), selector); > + voltage = _regulator_get_voltage(rdev); > + if (voltage >= 0) > + _notifier_call_chain(rdev, > + REGULATOR_EVENT_VOLTAGE_CHANGE, > + (void *)voltage); > + } > + trace_regulator_set_voltage_complete(rdev_get_name(rdev), ret); Hrm, I know we discussed this offline but now that I see the actual code for the full change here I'm a bit worried about the performance impact from calling get_voltage() again with devices that don't cache the register map (it'll be negligable for those that do). Looking a bit at the context I think probably what we want to do here is directly call list_voltage() for the selector we've just set so that the driver doesn't end up going back to the hardware to read the register value. Another option is to look at the notifier chain to see if there's any actual users but that seems more complicated and less abstracted. We definitely do want to pass the voltage out, now that I see this I seem to remember that the reason we don't is exactly the performance concern above but that all predates the use of selectors here which means we should be able to avoid the I/O costs.
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