Re: [Qemu-devel] [PATCH 1/4] Split serial-isa into its own config option

[David Gibson]

On Mon, Jun 29, 2015 at 12:12:01PM +0200, Andreas Färber wrote:
> Am 29.06.2015 um 07:36 schrieb David Gibson:
> > At present, the core device model code for 8250-like serial ports
> > (serial.c) and the code for serial ports attached to ISA-style legacy IO
> > (serial-isa.c) are both controlled by the CONFIG_SERIAL variable.
> > 
> > There are lots and lots of embedded platforms that have 8250-like serial
> > ports but have never had anything resembling ISA legacy IO.  Therefore,
> > split serial-isa into its own CONFIG_SERIAL_ISA option so it can be
> > disabled for platforms where it's not appropriate.
> > 
> > For now, I enabled CONFIG_SERIAL_ISA in every default-config where
> > CONFIG_SERIAL is enabled, excepting microblaze, xtensa and or32.  Those
> > platforms have technically lost functionality, but since they have no
> > other PCI or ISA devices, it's fairly clear they never actually used
> > leagacy IO stuff.
> 
> I think we can add moxie to that list, I'd be very surprised if it uses
> ISA. Applies also to 2/4. CC'ing the maintainer.

Right.  I'm being deliberately conservative in what I removed here.
With this patch in place it's easy for boards to remove ISA serial
support in future, but that seems like a change best made by the
people who actually know the boards.

> Which arm machines use ISA?

I don't know, but the point was I couldn't quickly convince myself
that none did.

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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