Re: Moving staging:iio over to threaded interrupts.

[Thomas Gleixner <tglx@linutronix.de>]

On Tue, 8 Mar 2011, Jonathan Cameron wrote:
> On 03/08/11 10:30, Thomas Gleixner wrote:
> > So now you can request the interrupts for your subdevices with
> > request_irq or request_threaded_irq.
> > 
> > You can also implement #1 this way, you just mark the sub device
> > interrupts as IRQ_NESTED_THREAD, and then call the handlers from the
> > main trigger irq thread.
> Hi Thomas,
> 
> One issue here that I'm not quite sure how to overcome is that the trigger to
> device mapping tends to be dynamic.  That is we quite often switch around
> what device is triggered by which trigger at runtime.  All done via text label
> matching via sysfs.

Was not aware of that.
 
> I guess we could maintain this by a spot of indirection and pool of interrupts per
> trigger (with compile time control on how many). Any other approaches come to mind?

That should work. You just need a function in the trigger
implementation which hands back an unused irq number to the device
when a trigger is installed for a device. Then the device calls
request[_threaded]_irq() on that irq number and all should work
magically.

Thanks,

	tglx