Messages in this thread | | | Date | Fri, 19 Oct 2007 13:57:33 +0100 (BST) | From | "Maciej W. Rozycki" <> | Subject | Re: [PATCH] PHYLIB: IRQ event workqueue handling fixes |
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On Fri, 19 Oct 2007, Jarek Poplawski wrote:
> But then... your patch seems to make it possible, because it enables > irq to the initial state of the counter. Of course, this could happen > on closing only.
That's because free_irq() does not disable the interrupt in the correct manner. The scenario is more or less like this:
phy_interrupt() [depth == 0] disable_irq() depth++; status |= IRQ_DISABLED; ... free_irq() [depth == 1] status |= IRQ_DISABLED; ... phy_change() [depth == 1] enable_irq() depth--; status &= ~IRQ_DISABLED; oops!
Now if free_irq() correctly incremented the depth counter, then the last enable_irq() would still decrement it, but with its initial value of 2 it would not change the status to reenable the line.
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