Re: Why does handle_simple_irq() require IRQ's to be disabled?

From: Thomas Gleixner
Date: Tue Jun 07 2011 - 04:26:35 EST


On Tue, 7 Jun 2011, David Jander wrote:
> On Mon, 6 Jun 2011 18:18:41 +0200 (CEST)
> Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
> > handle_nested_irq() is your friend.
>
> Thanks! This worked without disabling IRQ's.
> One last question, though:
>
> I set up the handler using irq_set_chip_and_handler(irq, ...,
> handle_simple_irq);
> From the interrupt thread, I call handle_nested_irq(). Is it OK, that in this
> case, the defined handler function (handle_simple_irq) is not used? Does this
> still make sense? Wouldn't calling just irq_set_chip() be enough here (it
> seems to work correctly)?

It should be enough. Though you should mark the demuxed interrupts
with irq_set_nested_thread(irqnr, true). That avoids that you create
extra threads for the demuxed interrupts which are never used.

Thanks,

tglx
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