On Sun, Feb 10, 2013 at 11:36 AM, Geert Uytterhoeven
<geert@xxxxxxxxxxxxxx> wrote:
On Thu, Jan 31, 2013 at 1:23 AM, Michael Schmitz <schmitzmic@xxxxxxxxx> 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.
No comments/suggestions?
Thanks again!
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 <schmitz@xxxxxxxxxx>
---
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 -- geert@xxxxxxxxxxxxxx
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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