@@ -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);
}
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 <mmogilvi_qemu@miniinfo.net> --- hw/i8259.c | 26 +++++++++----------------- 1 file changed, 9 insertions(+), 17 deletions(-)