Re: quiet irq 9

[KIYOHARA Takashi <kiyohara%kk.iij4u.or.jp@localhost>]

Hi! tsutsui-san,


From: Izumi Tsutsui <tsutsui%ceres.dti.ne.jp@localhost>
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