Re: use interrupt without clearing ?

[Ran Shalit <ranshalit@gmail.com>]

On Mon, Oct 12, 2015 at 5:53 AM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> On Sun, 2015-10-11 at 15:13 +0300, Ran Shalit wrote:
>> Hello,
>>
>> Is it possible to register an interrupt (in linux), without using the
>> automatic clear of interrupt.
>> I need this just for testing.
>
> Hi Ran,
>
> You need to give us much more info than that before anyone will be able to
> answer your question. Linux runs on lots of different powerpc machines, so
> without knowing what hardware you're talking about it's impossible to
> answer.
>
> cheers
>
>

Hi,

The interrupt for external IRQ.
It is configured in device tree as following:


intc4@0{
compatible = "intc4";
 #address-cells = <1>;
 #size-cells = <0>;
 reg = <0 0x1000>;
 interrupts = <20 0x8> ;
 interrupt-parent = <&ipic>;
};

It works OK (with normal clearing of interrupt), but we need to
implement a testing requirement as following (startup BIT  testing):

1. an interrupt is given - and not being cleared automatically
2. need to validate that there is a pending interrupt
3. and then we can clear the interrupt and restore the mechnism to its
normal usage (automatic cleari of interrupt)

Regards,
Ran