Re: quiet irq 9

Hi! tsutsui-san,


From: Izumi Tsutsui <[email protected]>
Date: Thu, 19 Jun 2008 22:43:53 +0900

> > Does this mean interrupt will not happen in after EOI is issued by
> > mistake at happening of interrupt in i8259 in a word?
> 
> When I wrote EOI code in cobalt/interrupt.c:icu_intr(),
> I wondered whether EOI should be sent before calling
> interrupt handlers to avoid possible race, but some other
> 8259 code (algor/pci/pcib.c etc.) did send EOI after
> calling handlers, so I left it.

I try to issue EOI before calling intrrupt handlers. However i8259 not 
respond.

Index: interrupt.c
===================================================================
RCS file: /cvsroot/src/sys/arch/cobalt/cobalt/interrupt.c,v
retrieving revision 1.3
diff -u -r1.3 interrupt.c
--- interrupt.c	14 May 2008 13:29:27 -0000	1.3
+++ interrupt.c	21 Jun 2008 01:33:59 -0000
@@ -333,6 +333,20 @@
 			irq = OCW3_POLL_IRQ(ICU2_READ(PIC_OCW3)) + 8;
 		}
 
+#if 1
+{
+int _irq = irq;
+		/* issue EOI to ack */
+		if (_irq >= 8) {
+			ICU2_WRITE(PIC_OCW2,
+			    OCW2_SELECT | OCW2_SL | OCW2_EOI |
+			    OCW2_ILS(_irq - 8));
+			_irq = IRQ_SLAVE;
+		}
+		ICU1_WRITE(PIC_OCW2,
+		    OCW2_SELECT | OCW2_SL | OCW2_EOI | OCW2_ILS(_irq));
+}
+#endif
 		icu_intrtab[irq].intr_evcnt.ev_count++;
 		LIST_FOREACH(ih, &icu_intrtab[irq].intr_q, ih_q) {
 			if (__predict_false(ih->ih_func == NULL))
@@ -343,6 +357,7 @@
 			}
 		}
 
+#if 0
 		/* issue EOI to ack */
 		if (irq >= 8) {
 			ICU2_WRITE(PIC_OCW2,
@@ -352,6 +367,7 @@
 		}
 		ICU1_WRITE(PIC_OCW2,
 		    OCW2_SELECT | OCW2_SL | OCW2_EOI | OCW2_ILS(irq));
+#endif
 	}
 }
 

Have you good idea?

Thanks,
--
kiyohara