On Tue, Sep 04, 2018 at 10:10:24AM -0500, Andrew F. Davis wrote: > On 09/04/2018 09:55 AM, Mark Brown wrote:
> > you get to keep the pieces" territory. If we really want to have a way > > of explicitly specifying that some widgets should never be turned on > > then it feels like rather than have something device and widget specific > > like this we should instead have a higher level way of doing that which > > can be applied to any widget, that is something that could be useful > > especially with things like speaker drivers where there's real potential > > for physical damage to the system. > Not sure how that could even look, it would need to be in DT as only > that layer knows the connections, but then the it would also have to > have internal knowledge of the widgets used in the driver.. We already have a bunch of DT code that knows about and uses the external widgets the device has (which are I'd guess the only ones where this is an issue)? I was thinking just have a property that lists the widgets that should never be turned on. > > Like I said in my original reply I'm also worried that this will break > > existing boards by causing them to change to a voltage of 0 when they > > had managed to end up with the default of 2V which happened to work for > > them. > Then only time this could happen is if they specified MICBIAS_OFF in DT > but got the default 2v instead. In which case, yes, the behavior would > change, but it would also be changing to the correct behavior. We can't > avoid fixing code on the off chance someone depended on the broken > behavior, no progress could ever be made. I'm really having a lot of trouble seeing MICBIAS_OFF as a useful voltage to specify in DT in the first place.
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