Re: [Qemu-devel] [PATCH 1/6] Split serial-isa into its own config option

[Markus Armbruster <armbru@redhat.com>]

David Gibson <david@gibson.dropbear.id.au> writes:

> 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_ISA 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 and xtensa, where it's
> pretty clear there isn't legacy IO stuff.

Related: in PATCH 6, you configure ISA support away for a bunch of
machines.  This includes device isabus-bridge.  You keep it for machines
sporting PCI.

> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
>  default-configs/alpha-softmmu.mak    | 1 +
>  default-configs/arm-softmmu.mak      | 1 +
>  default-configs/i386-softmmu.mak     | 1 +
>  default-configs/mips-softmmu.mak     | 1 +
>  default-configs/mips64-softmmu.mak   | 1 +
>  default-configs/mips64el-softmmu.mak | 1 +
>  default-configs/mipsel-softmmu.mak   | 1 +
>  default-configs/moxie-softmmu.mak    | 1 +
>  default-configs/ppc-softmmu.mak      | 1 +
>  default-configs/ppc64-softmmu.mak    | 1 +
>  default-configs/ppcemb-softmmu.mak   | 1 +
>  default-configs/sh4-softmmu.mak      | 1 +
>  default-configs/sh4eb-softmmu.mak    | 1 +
>  default-configs/sparc64-softmmu.mak  | 1 +
>  default-configs/x86_64-softmmu.mak   | 1 +
>  hw/char/Makefile.objs                | 3 ++-
>  16 files changed, 17 insertions(+), 1 deletion(-)

In addition for not adding CONFIG_SERIAL_ISA to microblaze and xtensa,
you don't seem to add it to or32.  If that's correct, please adjust your
commit message.

Quick check for machines sporting no ISA device other than isa-serial:

    $ for i in *-softmmu/qemu-system*; do echo -e 'info qdm\nq' | $i -S -M none -monitor stdio -display none | grep -v '^name "isa-serial"' | grep -q 'bus ISA' || echo $i; done
    aarch64-softmmu/qemu-system-aarch64
    arm-softmmu/qemu-system-arm
    cris-softmmu/qemu-system-cris
    lm32-softmmu/qemu-system-lm32
    m68k-softmmu/qemu-system-m68k
    microblaze-softmmu/qemu-system-microblaze
    microblazeel-softmmu/qemu-system-microblazeel
    or32-softmmu/qemu-system-or32
    s390x-softmmu/qemu-system-s390x
    tricore-softmmu/qemu-system-tricore
    xtensa-softmmu/qemu-system-xtensa
    xtensaeb-softmmu/qemu-system-xtensaeb

Same check for PCI devices:

    cris-softmmu/qemu-system-cris
    lm32-softmmu/qemu-system-lm32
    microblaze-softmmu/qemu-system-microblaze
    microblazeel-softmmu/qemu-system-microblazeel
    moxie-softmmu/qemu-system-moxie
    or32-softmmu/qemu-system-or32
    sparc-softmmu/qemu-system-sparc
    tricore-softmmu/qemu-system-tricore
    unicore32-softmmu/qemu-system-unicore32
    xtensa-softmmu/qemu-system-xtensa
    xtensaeb-softmmu/qemu-system-xtensaeb

Machines with neither kind of device:

    cris-softmmu/qemu-system-cris
    lm32-softmmu/qemu-system-lm32
    microblaze-softmmu/qemu-system-microblaze
    microblazeel-softmmu/qemu-system-microblazeel
    or32-softmmu/qemu-system-or32
    tricore-softmmu/qemu-system-tricore
    xtensa-softmmu/qemu-system-xtensa
    xtensaeb-softmmu/qemu-system-xtensaeb

I figure none of them has a use for isa-serial after PATCH 6.  Shouldn't
we drop CONFIG_SERIAL_ISA for all of them, not just microblaze, xtensa
and or32?

Patch looks good otherwise.