On Thu, Jan 31, 2013 at 1:23 AM, Michael Schmitz <schmitz...@gmail.com> wrote:
> [PATCH 09/17] [m68k] IRQ: add handle_polled_irq() for timer based soft
> interrupts -
> experimental hack to avoid unhandled interrupt timer to fire
> on EtherNEC/NetUSBee cards that have no hardware interrupt
> and need to be polled from a timer
>
> This patch adds a special 'polled interrupt' handler for timer based software
> interrupts.
Adding Thomas and lkml.
> handle_simple_irq() will respond to excessive unhandled interrupts (as are
> expected for a
> polling timer interrupt) by disabling the apparently unhandled interrupt
> source.
>
> handle_polled_irq() prevents this by setting the IRQS_POLL_INPROGRESS flag
> which will cause
> the unhandled interrupt events to be ignored.
>
> This is a temporary hack to allow timer based polling of the Atari ROM port
> network and USB
> cards only. Suggestions on how to properly handle this in the normal
> interrupt framework are
> most welcome.
>
> Signed-off-by: Michael Schmitz <schm...@debian.org>
> ---
> include/linux/irq.h | 1 +
> kernel/irq/chip.c | 36 ++++++++++++++++++++++++++++++++++++
> 2 files changed, 37 insertions(+), 0 deletions(-)
>
> diff --git a/include/linux/irq.h b/include/linux/irq.h
> index fdf2c4a..39bfcff 100644
> --- a/include/linux/irq.h
> +++ b/include/linux/irq.h
> @@ -407,6 +407,7 @@ extern void handle_fasteoi_irq(unsigned int irq, struct
> irq_desc *desc);
> extern void handle_edge_irq(unsigned int irq, struct irq_desc *desc);
> extern void handle_edge_eoi_irq(unsigned int irq, struct irq_desc *desc);
> extern void handle_simple_irq(unsigned int irq, struct irq_desc *desc);
> +extern void handle_polled_irq(unsigned int irq, struct irq_desc *desc);
> extern void handle_percpu_irq(unsigned int irq, struct irq_desc *desc);
> extern void handle_percpu_devid_irq(unsigned int irq, struct irq_desc *desc);
> extern void handle_bad_irq(unsigned int irq, struct irq_desc *desc);
> diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
> index 3aca9f2..ae7ef4d 100644
> --- a/kernel/irq/chip.c
> +++ b/kernel/irq/chip.c
> @@ -339,6 +339,42 @@ out_unlock:
> }
> EXPORT_SYMBOL_GPL(handle_simple_irq);
>
> +/**
> + * handle_polled_irq - Simple and software-decoded IRQs.
> + * @irq: the interrupt number
> + * @desc: the interrupt description structure for this irq
> + *
> + * Polled interrupts are sent from a demultiplexing software interrupt
> + * handler, where no interrupt hardware control is necessary.
> + */
> +void
> +handle_polled_irq(unsigned int irq, struct irq_desc *desc)
> +{
> + raw_spin_lock(&desc->lock);
> +
> + if (unlikely(irqd_irq_inprogress(&desc->irq_data)))
> + if (!irq_check_poll(desc))
> + goto out_unlock;
> +
> + desc->istate &= ~(IRQS_REPLAY | IRQS_WAITING);
> + kstat_incr_irqs_this_cpu(irq, desc);
> +
> + if (unlikely(!desc->action || irqd_irq_disabled(&desc->irq_data))) {
> + desc->istate |= IRQS_PENDING;
> + goto out_unlock;
> + }
> +
> + desc->istate |= IRQS_POLL_INPROGRESS;
> +
> + handle_irq_event(desc);
> +
> + desc->istate &= ~(IRQS_POLL_INPROGRESS);
> +
> +out_unlock:
> + raw_spin_unlock(&desc->lock);
> +}
> +EXPORT_SYMBOL_GPL(handle_polled_irq);
> +
> /*
> * Called unconditionally from handle_level_irq() and only for oneshot
> * interrupts from handle_fasteoi_irq()
> --
> 1.7.0.4
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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