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    SubjectRe: [PATCH 17/26] ARM: pxa: pxa95x is incompatible with earlier pxa
    On Sun, Oct 9, 2011 at 2:36 PM, Eric Miao <> wrote:
    > On Sun, Oct 9, 2011 at 2:21 PM, Haojian Zhuang <> wrote:
    >> On Sat, Oct 8, 2011 at 9:24 PM, Arnd Bergmann <> wrote:
    >>> On Saturday 08 October 2011 11:32:14 Haojian Zhuang wrote:
    >>>> Eric,
    >>>> At first, a new macro (ARCH_PXA_V7) is defined in
    >>>> arch/arm/mach-pxa/Kconfig in this patch.
    >>>> I prefer to move this macro to arch/arm/Kconfig.
    >>> If we move it to arch/arm/Kconfig, I would prefer making it a global option,
    >>> not a pxa specific one. If we introduce a top-level CONFIG_CPU_V6PLUS
    >>> option, we can make a number of decisions inside of Kconfig depend on that,
    >>> especially as we move to allow building multiple v6/v7 platforms together,
    >>> or multiple v5 platforms for that matter. I believe we don't need to
    >>> worry about v5+v7 at this point and can instead assume that won't ever
    >>> happen.
    >> Nobody is using PJ4 as v6 architecture now. CPUv6 is used in old stepping
    >> of Dove and MMP2. CPU_PJ4 only enables CPU_v7 in the mainline code.
    >> If we used ARCH_PXA_V7 in arch/arm/Kconfig, we would have two ARCH for
    >> pxa. One is ARCH_PXA, and the other is ARCH_PXA_V7. Those v5 machine
    >> should be based on ARCH_PXA. And the saarb, tavorevb3 should be based
    >> on ARCH_PXA_V7. So we can avoid to define PXA_V7_MACH_AUTO. I think
    >> the logic of Kconfig could be easier.
    >ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA7iMTlInbItkRaH3yJidg18Bg1SyIYZhbgu4jKpRkG4vavWebU6FwjovIuXoJqWzQimP4dvF4LWVq1xW84jtds8hRIc0a9nI1o2DUyqFzYvHHbqjXq+AJCqmUCaf9mlGn5/Ocd4LDbZKff3rHApCZrP4J/5beIiBDX25sFyRPNFjakJp5FbqwT17L91900rj7O60UeTe/vI9Gaf/oIvxMYriDmF02vsQgNqVNUzFllB8VTVb5HprZFZFX0ulBWhgTfMNqrhcZAxKwAW8tAY2zqa7NZZQhw0Ea8IkZrwA4qAwjQHwY56mNL7JRFLKlLVt3dEfkgx/HHWS8v1D80VGXUw== zhouhong@zhouhong-desktop
    > Haojian,
    > PXA_V7_MACH_AUTO is to by default auto enable tavorevb3 when
    > ARCH_PXA_V7 is selected.
    >>>> Secondly, pxa95x is both used in saarb and tavorevb3.
    >>> The patch makes that very explicit, doesn't it?
    >> +config PXA_V7_MACH_AUTO
    >> +       def_bool y
    >> +       depends on ARCH_PXA_V7
    >> +       depends on !MACH_SAARB
    >> +       select MACH_TAVOREVB3
    >> +
    >> Please check this. In your patch, SAARB and TAVOREVB3 is a mutex.
    > They are actually not mutually exclusive - it's a trick we use to select
    > MACH_TAVOREVB3 by default but this option also disappears once SAARB
    > is selected.
    OK. Could I know why saarb should be deselected while tavorevb3 is selected?

    > Arnd,
    > The 'depends on ARCH_PXA_V7' could actually be removed here, as the
    > option is already encapsulated in if ARCH_PXA_V7 ... endif. And this
    > trick won't work very well when there are more than 2 boards.
    >>>> Thirdly, PXA_V7_MACH_AUTO is unnecessary. We just need to select those
    >>>> machines in defconfig or define a new DT machine type to select all
    >>>> machines.
    >>> Enabling them in defconfig will not help here, it still allows creating
    >>> an invalid configuration by disabling both saarb and tavorevb3.
    >>> I agree that it would be best to have a single DT machine type that can
    >>> handle both saarb and tavorevb3 as well as any future pxa95x based machines,
    >>> but nobody has implemented that yet. In the meantime, I think we should
    >>> have the PXA_V7_MACH_AUTO or an equivalent mechanism to enforce that at
    >>> least one of the two board files gets built into any kernel. This is mostly
    >>> important to help the 'make randconfig' builds succeed, not for actual
    >>> users getting it wrong accidentally.
    >>>        Arnd
    >> Exactly we need to define a single DT machine type in both arch-pxa
    >> and arch-mmp.
    >> I'll register it first.
    > Please go ahead.
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      Last update: 2011-10-09 08:41    [W:0.034 / U:87.840 seconds]
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