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    SubjectRe: [PATCH v2] net: rfkill: add generic gpio rfkill driver
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    On Thu, 2011-05-12 at 11:40 -0700, Johannes Berg wrote:
    > On Thu, 2011-05-12 at 11:23 -0700, Rhyland Klein wrote:
    >
    > > > Are you sure starting out with UNSPECIFIED works? Then you'll always
    > > > change, but if the clock was enabled already you still enable it on the
    > > > first set_block() from rfkill, which still has the refcount problem, no?
    > > > It seems to me that the original state has to be passed in from the
    > > > platform?
    >
    > > I thought about that. But I decided the clock that it is possible to
    > > have the clock used for the radio used for something else right?
    >
    > Sure.
    >
    > > in
    > > which case, the driver will leave the clk in whatever state it initially
    > > finds it. I.e. if the clock is disabled, then it will enable it only
    > > once and work, if it is enabled, it will add a refcount (only once) and
    > > then work and disable it again only once. It never changes the refcount
    > > in either direction by more than 1, and this way the initial setting of
    > > the clock is irrelevant. The board files can simply initialize the block
    > > as off if that is the initial clk state they want.
    >
    > The issue is that depending on how you boot, the first refcount change
    > might be +1 or it might be -1.
    >
    > If rfkill decides that at the time of loading wifi should be off, then
    > the first change would be -1, and after that it would flip between 0 and
    > -1.
    >
    > If, on the other hand, rfkill decides that at the time of loading the
    > driver wifi should be on, then the first change would be +1 and it'll
    > flip between 0 and +1.
    >
    > This seems like it'll cause issues at some point, so I think you should
    > either allow the driver to set the initial state or hardcode one of
    > these possibilities (so at least it's predictable)
    >
    > johannes
    >

    I won't go negative, if you look, it only will disable clock if it knows
    it has already enabled it.

    rhyland



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