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

From: Daniel Walker
Date: Wed Nov 28 2007 - 15:53:20 EST


On Wed, 2007-11-28 at 15:16 -0500, Steven Rostedt wrote:

>
> This could also simply be unique to the interrupt threads (only in RT). So
> perhaps the patch is OK.
>
> Remy, sorry about this round-a-bout. But I don't have any of the hardware
> that this affects, and I'm just being cautious.

Ignoring the ARM side of things for a sec, handle_simple_irq() will
mask() the interrupt in the special case that an interrupt is already in
the processes of being handled.. handle_simple_irq() also unmasks when
it finishes handling an interrupt (something real time adds for some
reason) ..

In terms of threading the irq everything is the same except there is no
unmask() call when the thread finishes ..

Daniel

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/