[coreboot] Interesting device enumeration problem

Myles Watson mylesgw at gmail.com
Tue Jul 7 23:31:42 CEST 2009

> > I think crystal clear terminology will be difficult to come up with
> here.
> >
> I remember having the same problem in v3 dts. Basically, there are four
> possible states I can think of for devices:
> 1. Enabled
The most common case.

> 2. Disabled
So does this mean "not enabled?"

> 3. Ignored
Meaning that it isn't touched at all.

> 4. Hidden
Meaning that it doesn't respond.

> (5. Configured, but enable not touched)
I guess this one is ambiguous to me.

> Not all states are possible on all chipsets, but from time to time one
> of the functions is needed. By the way, we have various problems on
> SuperI/O chips where we want to configure GPIOs with their own LDN and
> the constraint is that the usual enable bit must not be set for the GPIO
> LDN.
I think things like that have to be handled in device-specific code.  It
seems unlikely that we could handle that correctly from the Config files.


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