Re: [PATCH PREEMPT_RT]: On AT91 ARM: GPIO Interrupt handlingcan/will stall forever

From: Daniel Walker
Date: Tue Nov 27 2007 - 11:01:51 EST


On Tue, 2007-11-27 at 07:25 -0800, Daniel Walker wrote:
> On Tue, 2007-11-27 at 10:11 -0500, Steven Rostedt wrote:
> > Thomas,
> >
> > Can you ACK or NACK this patch. I know you play with a bunch of
> > hardware that this patch may affect.
> >
>
> My two cents, I think it's needed (or something like it).. It looks like
> handle_simple_irq normally expects a custom cascade type handler to
> unmask on return. When you switch to a threaded handler the cascade
> handler is gone and can't unmask..

I take this back .. The comment at the top of handle_simple_irq() is,

* Note: The caller is expected to handle the ack, clear, mask and
* unmask issues if necessary.


So we shouldn't need any flow control unless there is some other
factors..

Additionally, we have a patch in the real time tree called
"irq-mask-fix.patch" which adds an "unmask" to handle_simple_irq, but as
the note says we don't need flow control..

Daniel

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