Re: Disabling an interrupt in the handler locks the system up

From: Thomas Gleixner
Date: Fri Oct 21 2016 - 15:52:10 EST


On Fri, 21 Oct 2016, Mason wrote:
> On 21/10/2016 21:14, Marc Zyngier wrote:
> > If connecting a device that signals its interrupt as level low to an
> > input line configured as level high doesn't strike you as a major
> > issue, nothing will. At that point, you can put anything you want in
> > your DT.
>
> If I understand correctly, you are saying that I should have
> specified IRQ_TYPE_LEVEL_LOW, instead of IRQ_TYPE_LEVEL_HIGH?
>
> If the HW outputs 1 when idle, and 0 when busy, that
> is level low? (Sorry if this is obvious, I'm absolutely
> clueless in this subject matter.)

We describe the level which is raising the interrupt. So in your case the
line goes to 0 when the interrupt is active, so the level is LOW.

Thanks,

tglx