Re: [PATCH v4 1/5] gadget: Introduce the notifier functions

From: Pavel Machek
Date: Thu Oct 08 2015 - 11:51:13 EST


Hi!

> > What's the advantage of pushing this to userspace? By the time we
> > provide enough discoverability to enable userspace to configure itself
> > it seems like we'd have enough information to do the job anyway.
>
> you're going to be dealing with a setup where each vendor does one thing
> differently. Some will have it all in the SoC part of a single IP (dwc3 can be
> configured that way), some will push it out to companion IC, some might even use
> some mostly discrete setup and so on...
>
> We're gonna be dealing with a decision that involves information from multiple
> subsystems (USB, regulator, hwmon, power supply to name a few).
>
> We tried doing it all in the kernel back in N800, N810 and N900/N9 days and it's
> just plain difficult. To make matters worse, N900 had two USB PHYs, one for
> actual runtime use and another just for detecting the charger type on the other
> end.

N900 does charging from kernel these days.

Not being able to boot generic distribution would be regression there...

Pavel
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