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    SubjectRe: [PATCH v3] gpio: interrupt consistency check for OF GPIO IRQs
    On Wed, Sep 04, 2013 at 02:16:36PM -0600, Stephen Warren wrote:
    > On 09/04/2013 03:05 AM, Lars Poeschel wrote:

    > > The driver that tries to use the GPIO requested by this patch before HAS to
    > > fail. This is exactly the intention of this patch. We don't want the GPIO to
    > > be requested any more, if it is used as an interrupt pin.

    > That will break existing drivers. There are drivers that request the
    > same GPIO and IRQ. IIRC, the SDHCI CD (Card Detect) GPIO is requested
    > that way.

    Yes, plus input devices and audio jack detection among others. This
    pattern is very common if the GPIO is actually being used as a GPIO, an
    edge triggered interrupt is used to flag when something happens and the
    state is determined by reading the GPIO state (often with some
    debounce).
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