Messages in this thread | | | From | Lars Poeschel <> | Subject | Re: [PATCH v3] gpio: interrupt consistency check for OF GPIO IRQs | Date | Tue, 10 Sep 2013 10:47:55 +0200 |
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On Tuesday 10 September 2013 17:19:24, Mark Brown wrote: > 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).
And I say it again for those coming into the discussion late, like it has been said many many times before: This patch does not break any of this drivers. They simply request their GPIO from DT and turn it into an irq using gpio_to_irq, request that irq on their behalf and use it as GPIO and IRQ in parallel. At least this is not a problem.
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