Re: Debugging Thinkpad T430s occasional suspend failure.

From: Linus Torvalds
Date: Sun Feb 17 2013 - 12:32:40 EST


On Sun, Feb 17, 2013 at 7:11 AM, Frederic Weisbecker <fweisbec@xxxxxxxxx> wrote:
>
> preempt_value_in_interrupt() looks buggy in your patch: it makes
> invoke_softirq() returning if (val & HARDIRQ_MASK). But that's always
> true since you have moved further the sub_preempt_count(IRQ_EXIT)
> further.

No, that's not it. The value hasn't been written back yet, but it already did:

+ int offset = IRQ_EXIT_OFFSET;
+ int count = preempt_count() - offset;

so the 'count' has the IRQ_EXIT_OFFSET already subtracted. So no,
HARDIRQ_MASK is *not* always set.

Linus
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