Re: linux/kernel/irq/chip.c IRQ disable, shutdown bug

From: Andrew Morton
Date: Sat Feb 23 2008 - 03:25:18 EST


On Fri, 15 Feb 2008 14:10:18 -0000 "Hennerich, Michael" <Michael.Hennerich@xxxxxxxxxx> wrote:

> free_irq() does not disable/mask the irq, in case disable or shutdown in struct irq_chip is left uninitilazied.
>
> /**
> * struct irq_chip - hardware interrupt chip descriptor
> *
> * @name: name for /proc/interrupts
> * @startup: start up the interrupt (defaults to ->enable if NULL)
> * @shutdown: shut down the interrupt (defaults to ->disable if NULL)
> * @enable: enable the interrupt (defaults to chip->unmask if NULL)
> * @disable: disable the interrupt (defaults to chip->mask if NULL)
>
>
> According to linux/irq.h struct irq_chip information,
> chip->disable should default to chip->mask if NULL.
> However irq_chip_set_defaults(struct irq_chip *chip) will set it to default_disable a empty function.
>
>
> Looking through various architectures, it's pretty common that disable and shutdown is NULL.
> So this bug affects many architectures.
>
> This patch fixes the issue.
>

Please send a Signed-off-by: for this work, as per
Documentation/SubmittingPatches, thanks.


> Index: irq/chip.c
> ===================================================================
> --- irq/chip.c (revision 4276)
> +++ irq/chip.c (working copy)

Please prepare future patches in `patch -p1' form. This should have been

> --- a/kernel/irq/chip.c
> +++ a/kernel/irq/chip.c


> @@ -233,6 +233,10 @@
> */
> static void default_disable(unsigned int irq)
> {
> + struct irq_desc *desc = irq_desc + irq;
> +
> + desc->chip->mask(irq);
> + desc->status |= IRQ_MASKED;
> }
>
> /*

Ingo, Thomas: ack?
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