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    SubjectRe: [git pull] fastboot tree for v2.6.28

    * Arjan van de Ven <> wrote:

    > > You can try to convince me otherwise, but I really do think this
    > > patch is fundamentally the wrong approach.
    > there's an angle here which I would like to bring up. There is a
    > fundamental difference between a spider functionality like USB, and
    > "leaf drivers". Yes USB should do it right, it's drivers are
    > effectively a midlayer. (and again, pull gregkh's tree and you'll get
    > that; although even with that there's a noticeable amount of time
    > spent there).
    > For leaf drivers, it's a matter of where you want to push the
    > functionality. With leaf drivers I mean things like the ACPI battery
    > driver (or other ACPI drivers), but also various PCI drivers that
    > don't have or are elaborate subsystems or boot dependencies. We could
    > make all their probing functions async in each driver, or we could
    > provide the most simple interface as is done in this case, they just
    > change how they declare their initcall. (I'll grant you that we could
    > also do a pci_register_device_async() like of helper, but that's just
    > solving part of the same problem)
    > Personally for leaf drivers, I think the initcall-level approach is
    > much less error prone.

    i'd like to inject my first-hand testing experience with your patches:

    When i saw your patches then initially my impression was "oh my, this
    will break a ton of stuff", so i asked you to: make it default-off
    (against Andrew's suggestion to just remove the config and make it a
    compulsory feature), to add various mechanisms to disable and isolate
    it, should it break something - which i expected to be a near certainty.

    But i was wrong. We had only a single bug in fastboot-v1 three months
    ago which i bisected back to this series, and you fixed that quickly.
    And CONFIG_FASTBOOT=y is definitely one of the popular features that
    testers enable and there's all sorts of weird systems that are being
    tested with tip/master.

    So tip/fastboot has certainly been a problem free topic in its 3 months
    of lifetime - and it got propagated to linux-next early on as well.

    Our -tip testsystems boot with CONFIG_FASTBOOT=y about 50% of the time,
    once every couple of minutes on this test-system:


    i checked the logs, just yesterday that meant 354 fastboot-enabled
    bootups on just that single test-system. So while i fully expected
    fragility from this topic, neither our testing nor our testers saw
    fragility in practice.


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      Last update: 2008-10-11 09:05    [W:0.024 / U:28.520 seconds]
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