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Add a special check for a stray IRQ 7 or IRQ 15 to see if it is actually

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a spurious interrupt from one of the 8259As.  If so, don't log it as a
stray IRQ, but just silently ignore it.

Approved by:	re (rwatson)
This commit is contained in:
jhb 2003-11-19 15:40:23 +00:00
parent b9d42e49b0
commit cd693b0bad
1 changed files with 22 additions and 0 deletions
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22
sys/i386/isa/atpic.c
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@ -343,6 +343,28 @@ atpic_handle_intr(struct intrframe iframe)
KASSERT((uint)iframe.if_vec < ICU_LEN,
("unknown int %d\n", iframe.if_vec));
isrc = &atintrs[iframe.if_vec].at_intsrc;
/*
* If we don't have an ithread, see if this is a spurious
* interrupt.
*/
if (isrc->is_ithread == NULL &&
(iframe.if_vec == 7 || iframe.if_vec == 15)) {
int port, isr;
/*
* Read the ISR register to see if IRQ 7/15 is really
* pending. Reset read register back to IRR when done.
*/
port = ((struct atpic *)isrc->is_pic)->at_ioaddr;
mtx_lock_spin(&icu_lock);
outb(port, OCW3_SEL | OCW3_RR | OCW3_RIS);
isr = inb(port);
outb(port, OCW3_SEL | OCW3_RR);
mtx_unlock_spin(&icu_lock);
if ((isr & IRQ7) == 0)
return;
}
intr_execute_handlers(isrc, &iframe);
}