From 0b0a6778c96c3ac3e3f979d655de0ae595232507 Mon Sep 17 00:00:00 2001
From: Nathan Binkert <binkertn@umich.edu>
Date: Fri, 20 Aug 2004 11:40:57 -0400
Subject: [PATCH] Fixup interrupting of the ethernet device.

dev/ns_gige.cc:
    clean up the interrupt handling code so that it is simpler and
    less prone to bugs.  I hope I removed the bug where the:
    assert(intrTick >= curTick || intrTick == 0); would get triggered.
    I'm pretty sure that was due to intrTick not being cleared when
    the interrupt was cleared.

    This code probably still needs to be looked at more closely to
    make sure interrupts are not missed.

--HG--
extra : convert_revision : 61e2eb043540f2534a80c9b633006a71e7d6e282
---
 dev/ns_gige.cc | 72 ++++++++++++++++++++++++--------------------------
 1 file changed, 34 insertions(+), 38 deletions(-)

diff --git a/dev/ns_gige.cc b/dev/ns_gige.cc
index f7f56d39b..87ac5b593 100644
--- a/dev/ns_gige.cc
+++ b/dev/ns_gige.cc
@@ -987,61 +987,50 @@ NSGigE::cpuIntrPost(Tick when)
      * @todo this warning should be removed and the intrTick code should
      * be fixed.
      */
-    if (intrTick < curTick && intrTick != 0) {
-        warn("intrTick < curTick !!!  intrTick=%d curTick=%d\n",
-             intrTick, curTick);
-        intrTick = 0;
-    }
-    assert((intrTick >= curTick) || (intrTick == 0));
-    if (when > intrTick && intrTick != 0)
+    assert(when >= curTick);
+    assert(intrTick >= curTick || intrTick == 0);
+    if (when > intrTick && intrTick != 0) {
+        DPRINTF(EthernetIntr, "don't need to schedule event...intrTick=%d\n",
+                intrTick);
         return;
+    }
 
     intrTick = when;
-
-    if (intrEvent) {
-        intrEvent->squash();
-        intrEvent = 0;
+    if (intrTick < curTick) {
+        debug_break();
+        intrTick = curTick;
     }
 
-    if (when < curTick) {
-        cpuInterrupt();
-    } else {
-        DPRINTF(EthernetIntr,
-                "going to schedule an interrupt for intrTick=%d\n",
-                intrTick);
-        intrEvent = new IntrEvent(this, true);
-        intrEvent->schedule(intrTick);
-    }
+    DPRINTF(EthernetIntr, "going to schedule an interrupt for intrTick=%d\n",
+            intrTick);
+
+    if (intrEvent)
+        intrEvent->squash();
+    intrEvent = new IntrEvent(this, true);
+    intrEvent->schedule(intrTick);
 }
 
 void
 NSGigE::cpuInterrupt()
 {
-    // Don't send an interrupt if there's already one
-    if (cpuPendingIntr) {
-        DPRINTF(EthernetIntr,
-                "would send an interrupt now, but there's already pending\n");
-        intrTick = 0;
-        return;
-    }
-    // Don't send an interrupt if it's supposed to be delayed
-    if (intrTick > curTick) {
-        DPRINTF(EthernetIntr,
-                "an interrupt is scheduled for %d, wait til then\n",
-                intrTick);
-        return;
-    }
+    assert(intrTick == curTick);
 
     // Whether or not there's a pending interrupt, we don't care about
     // it anymore
     intrEvent = 0;
     intrTick = 0;
 
-    // Send interrupt
-    cpuPendingIntr = true;
+    // Don't send an interrupt if there's already one
+    if (cpuPendingIntr) {
+        DPRINTF(EthernetIntr,
+                "would send an interrupt now, but there's already pending\n");
+    } else {
+        // Send interrupt
+        cpuPendingIntr = true;
 
-    DPRINTF(EthernetIntr, "posting cchip interrupt\n");
-    tsunami->cchip->postDRIR(configData->config.hdr.pci0.interruptLine);
+        DPRINTF(EthernetIntr, "posting cchip interrupt\n");
+        tsunami->cchip->postDRIR(configData->config.hdr.pci0.interruptLine);
+    }
 }
 
 void
@@ -1050,6 +1039,13 @@ NSGigE::cpuIntrClear()
     if (!cpuPendingIntr)
         return;
 
+    if (intrEvent) {
+        intrEvent->squash();
+        intrEvent = 0;
+    }
+
+    intrTick = 0;
+
     cpuPendingIntr = false;
 
     DPRINTF(EthernetIntr, "clearing cchip interrupt\n");
-- 
2.30.2