Re: [PATCH v3 2/3] mfd: lubbock_io: add lubbock_io board

From: robert . jarzmik
Date: Wed Jan 21 2015 - 08:37:13 EST


> ----- Mail original -----
> De: "Lee Jones" <lee.jones@xxxxxxxxxx>
First of all, this is my web mail interface, so please be kind with
my mail formatting ...

> Looking at one of the other patches in the series it appears the flag
> you're trying to capture is IORESOURCE_IRQ_LOWEDGE. When I grep for
> where this is being _used_ (think 'consumed, rather than passed. I
> only see a single entry in drivers/pnp/interface.c.
Look at this call chain :
request_irq()
setup_irq()
__setup_irq()
__irq_set_trigger()
pxa_gpio_irq_type() (aka. chip->irq_set_type)
=> hardware register manipulation

Moreover, you should be aware of the bijection existing between :
- IORESOURCE_IRQ_LOWEDGE and IRQF_TRIGGER_RISING
- it's HIGHEDGE twin
- it is noted in : include/linux/interrupt.h

> That's what got me thinking... are you sure you're a) making use of
this flag
Yes, I'm quite sure.

> b) assuming the answer to 'a' is "no"
I won't :)

> I think to set an edge trigger on an IRQ, you should instead do so via
> irq_set_irq_type(), or have a missed a line or two?
__setup_irq(), that's the entry point.

Cheers.

--
Robert
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