Re: [PATCH 01/01] MFD: add ADC support to DA9052/53 MFD core v2

From: Ashish Jangam
Date: Tue Feb 21 2012 - 06:39:51 EST


> On Mon, Feb 20, 2012 at 12:07:27PM +0000, Arnd Bergmann wrote:
>
> > Also, I would recommend using request_irq instead of
> > request_threaded_irq here because the function only has a single
> > "complete()" call in it, just like a threaded IRQ handler has. There
> > is no point going through another thread just to wake up the one that is blocked.
>
> Actually in this case that won't work as the interrupt is generated by the chip interrupt controller and as the chip is I2C/SPI controlled it is itself threaded and can only generate threaded interrupts as genirq can't get back into hard interrupt context.
>
> As a result of this restriction when an interrupt handler doesn't care what context it runs in it's better to use request_any_context_irq().
> This will do a normal IRQ when it can but will bind successfully to a threaded IRQ if that's what's provided.

as threaded IRQs are only being used, request_any_context_irq() will
internally call request_threaded_irq() so is there any other need to
replace the current request_threaded_irq()?


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