Re: [Qemu-devel] [PATCH 2/4] Allow ISA bus to be configured out

[David Gibson]

On Tue, Jun 30, 2015 at 01:44:10PM +1000, David Gibson wrote:
> On Mon, Jun 29, 2015 at 12:26:50PM +0200, Andreas Färber wrote:
> > Am 29.06.2015 um 07:36 schrieb David Gibson:
> > > Currently, the code to handle the legacy ISA bus is always included in
> > > qemu.  However there are lots of platforms that don't include ISA legacy
> > > devies, and quite a few that have never used ISA legacy devices at all.
> > > 
> > > This patch allows the ISA bus code to be disabled in the configuration for
> > > platforms where it doesn't make sense.  For now, the default configs are
> > > adjusted to include ISA on all platforms including PCI (since
> > > CONFIG_IDE_CORE which is in pci.mak requires ISA support) and also several
> > > others which include ISA devices.  We may want to pare this down in 
> > > future.
> > 
> > PCI also allows to have a PCI-ISA bridge such as the i82378, which means
> > that all PCI platforms can potentially obtain an actual ISA bus. So at
> > least the commit message could use a makeover to avoid someone touching
> > IDE to blindly disable the dependency.
> 
> Sorry, I'm not quite following what you're getting at here.
> 
> > You'd also need to think about the qtests then:
> > 
> > $ git grep i82378 -- tests/
> > tests/endianness-test.c:    { "ppc", "g3beige", 0xfe000000, .bswap =
> > true, .superio = "i82378" },
> > tests/endianness-test.c:    { "ppc", "bamboo", 0xe8000000, .bswap =
> > true, .superio = "i82378" },
> > tests/endianness-test.c:    { "ppc64", "mac99", 0xf2000000, .bswap =
> > true, .superio = "i82378" },
> > tests/endianness-test.c:      .bswap = true, .superio = "i82378" },
> > tests/endianness-test.c:    { "sh4", "r2d", 0xfe240000, .superio =
> > "i82378" },
> > tests/endianness-test.c:    { "sh4eb", "r2d", 0xfe240000, .bswap = true,
> > .superio = "i82378" },
> 
> Ah, good point.  I'll need to rework for that,

Actually.. on second thoughts..

CONFIG_I82378 already exists, and will break those tests of disabled.

So while making the tests more robust against config changes would be
a good thing in general, I don't think it's in the scope of what I'm
trying to do here - making ISA configurable won't make these tests any
more broken with nonstandard configs than they already are.

-- 
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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