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[Qemu-devel] [PATCH v6 7/8] i8259: refactor pic_set_irq level logic
From: |
Matthew Ogilvie |
Subject: |
[Qemu-devel] [PATCH v6 7/8] i8259: refactor pic_set_irq level logic |
Date: |
Sun, 30 Sep 2012 22:56:37 -0600 |
No change in functionality.
Clarify that the only difference between level triggered and
edge triggered interrupts is on the leading edge.
Signed-off-by: Matthew Ogilvie <address@hidden>
---
hw/i8259.c | 26 +++++++++-----------------
1 file changed, 9 insertions(+), 17 deletions(-)
diff --git a/hw/i8259.c b/hw/i8259.c
index c011787..1ba9b3a 100644
--- a/hw/i8259.c
+++ b/hw/i8259.c
@@ -140,26 +140,18 @@ static void pic_set_irq(void *opaque, int irq, int level)
}
#endif
- if (s->elcr & mask) {
- /* level triggered */
- if (level) {
+ if (level) {
+ if ((s->last_irr & mask) == 0 || /* edge for edge triggered */
+ (s->elcr & mask)) { /* or level triggered */
s->irr |= mask;
- s->last_irr |= mask;
- } else {
- s->irr &= ~mask;
- s->last_irr &= ~mask;
}
+ s->last_irr |= mask;
} else {
- /* edge triggered */
- if (level) {
- if ((s->last_irr & mask) == 0) {
- s->irr |= mask;
- }
- s->last_irr |= mask;
- } else {
- s->irr &= ~mask;
- s->last_irr &= ~mask;
- }
+ /* Dropping level clears the interrupt regardless of edge trigger
+ * vs level trigger.
+ */
+ s->irr &= ~mask;
+ s->last_irr &= ~mask;
}
pic_update_irq(s);
}
--
1.7.10.2.484.gcd07cc5
- [Qemu-devel] [PATCH v6 0/8] i8254, i8259 and running Microport UNIX (ca 1987), Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 1/8] fix some debug printf format strings, Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 2/8] vl: fix -hdachs/-hda argument order parsing issues, Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 3/8] qemu-options.hx: mention retrace= VGA option, Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 5/8] i8254: fix inaccuracies in pit_get_out(), Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 4/8] vga: add some optional CGA compatibility hacks, Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 6/8] i8259: fix so that dropping IRQ level always clears the interrupt request, Matthew Ogilvie, 2012/10/01
- [Qemu-devel] [PATCH v6 7/8] i8259: refactor pic_set_irq level logic,
Matthew Ogilvie <=
- [Qemu-devel] [PATCH v6 8/8] i8259/i8254: migration workaround for timer, Matthew Ogilvie, 2012/10/01