Re: [PATCH] Add support for IRQ_NOAUTOEN in __set_irq_handler

From: Esben Haabendal
Date: Fri Jun 20 2008 - 04:20:18 EST


Currently, IRQ_NOAUTOEN is only supported with request_irq, and not fx.
set_irq_chained_handler(). As the IRQ_NOAUTOEN flag is silently ignored by
__set_irq_handler, you risk writing faulty code that start with irq enabled
although the developer expects irq disabled.

If the flag is not handled, wouldn't it make sense to return an error?

/Esben

On Thu, Jun 19, 2008 at 9:37 PM, Esben Haabendal <eha@xxxxxxxxxxxxxxxxxx> wrote:
>
> Any reason for __set_irq_handler not supporting the IRQ_NOAUTOEN flag?
>
> /Esben
>
> kernel/irq/chip.c | 11 ++++++++---
> 1 files changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 964964b..42bb163 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -584,10 +584,15 @@ __set_irq_handler(unsigned int irq,
> irq_flow_handler_t handle, int is_chained,
> desc->name = name;
>
> if (handle != handle_bad_irq && is_chained) {
> - desc->status &= ~IRQ_DISABLED;
> desc->status |= IRQ_NOREQUEST | IRQ_NOPROBE;
> - desc->depth = 0;
> - desc->chip->unmask(irq);
> + if (!(desc->status & IRQ_NOAUTOEN)) {
> + desc->depth = 0;
> + desc->status &= ~IRQ_DISABLED;
> + desc->chip->unmask(irq);
> + } else {
> + /* Undo nested disables: */
> + desc->depth = 1;
> + }
> }
> spin_unlock_irqrestore(&desc->lock, flags);
> }
--
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