Re: [PATCH v3] gpio: interrupt consistency check for OF GPIO IRQs

On Tuesday 10 September 2013 17:19:24, Mark Brown wrote:

On Wed, Sep 04, 2013 at 02:16:36PM -0600, Stephen Warren wrote:

quoted

On 09/04/2013 03:05 AM, Lars Poeschel wrote:

quoted

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.