Re: [PATCH 1/3] serial: 8250_early: Add earlycon support for AMD Carrizo / Stoneyridge

[Alan Cox]

On Mon, 26 Mar 2018 20:56:45 -0600
Aaron Durbin <adurbin@xxxxxxxxxxxx> wrote:

> On Mon, Mar 26, 2018 at 12:24 PM, Alan Cox <gnomes@xxxxxxxxxxxxxxxxxxx> wrote:
> >> Sadly, this situation
> >> is not unique to this hardware. There is hardware all over that does
> >> not meet the current assumptions being made in the early uart drivers
> >> within the kernel.  
> >
> > Is there any fundamental reason you can't just embed dt entries in the
> > ACPI table to describe the other features you need. I appreciate it
> > doesn't solve the generic PC case but it ought to help for anything where
> > the firmware cares about Linux ?  
> 
> What's the method for doing that? Using _DSD methods? Or have a
> pointer to examples? Sorry, I haven't spelunked into the current state
> of bridging ACPI and devicetree in a while.

ACPI 5.1 adds an _DSD method UUID for device properties.

The kernel device_property_* interface will pick them up just as if they
came from DT tables etc.

Alan