PERFORCE change 42358 for review

[Peter Wemm]

http://perforce.freebsd.org/chv.cgi?CH=42358

Change 42358 by peter at peter_daintree on 2003/11/14 11:10:16

	re-add spurious interrupt detection

Affected files ...

.. //depot/projects/hammer/sys/amd64/isa/atpic.c#20 edit

Differences ...

==== //depot/projects/hammer/sys/amd64/isa/atpic.c#20 (text+ko) ====

@@ -304,6 +304,22 @@
 
 	KASSERT(vec < ICU_LEN, ("unknown int %d\n", vec));
 	isrc = &atintrs[vec].at_intsrc;
+	if (vec == 7 || 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);
 }