Messages in this thread | | | Date | Tue, 16 Oct 2007 18:19:32 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | Re: [PATCH] PHYLIB: IRQ event workqueue handling fixes |
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On Tue, 16 Oct 2007, Jarek Poplawski wrote:
> Yes, it's all right here. Sorry for bothering - I should've found this > by myself.
Ah, no problem -- even with the right keys you may sometimes get lost in the results.
> I've still some doubts about this possible enable_irq() after > free_irq(). If it's the only handler the status would be changed again > and at least some of this code in check_irq_resend() would be run, but > I can miss something again or/and this doesn't matter, as well.
Well, enable_irq() and disable_irq() themselves are nesting, so they are not a problem. OTOH, free_irq() does not seem to maintain the depth count correctly, which looks like a bug to me and which could trigger regardless of whether flush_scheduled_work() or cancel_work_sync() was called.
The reason is CONFIG_DEBUG_SHIRQ which makes a simulated interrupt event be sent at the end of free_irq(). It looks like a problem that is complementary to one I signalled here:
http://lkml.org/lkml/2007/9/12/82
with respect to request_irq(), where, similarly, such an interrupt event is sent at the beginning. It looks like nobody was concerned back then, but perhaps it is time to do a better investigation now and propose a solution.
I'll think about it and thanks for your inquisitiveness that has led to these conclusions.
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