devices: undo cset 017baf09599f that added timer drain functions.

It's not the right fix for the checkpoint deadlock problem
Brad was having, and creates another bug where the system can
deadlock on restore.  Brad can't reproduce the original bug
right now, so we'll wait until it arises again and then try
to fix it the right way then.

6 files changed, 9 insertions, 80 deletions

diff --git a/src/dev/alpha/tsunami_io.cc b/src/dev/alpha/tsunami_io.cc
index 1a76c2c32..c90f06b5a 100644
--- a/src/dev/alpha/tsunami_io.cc
+++ b/src/dev/alpha/tsunami_io.cc
@@ -249,17 +249,6 @@ TsunamiIO::clearPIC(uint8_t bitvector)
     }
 }
 
-unsigned int 
-TsunamiIO::drain(Event *de)
-{
-    unsigned int count = 0;
-    count += pitimer.drain(de);
-    count += rtc.drain(de);
-    assert(count == 0);
-    changeState(SimObject::Drained);
-    return count;
-}
-
 void
 TsunamiIO::serialize(ostream &os)
 {
diff --git a/src/dev/alpha/tsunami_io.hh b/src/dev/alpha/tsunami_io.hh
index f649247e2..b6d63322b 100644
--- a/src/dev/alpha/tsunami_io.hh
+++ b/src/dev/alpha/tsunami_io.hh
@@ -141,12 +141,6 @@ class TsunamiIO : public BasicPioDevice
     void clearPIC(uint8_t bitvector);
 
     /**
-     * Drain the io state including all associated events.
-     * @param drainEvent
-     */
-    unsigned int drain(Event *de);
-
-    /**
      * Serialize this object to the given output stream.
      * @param os The stream to serialize to.
      */
diff --git a/src/dev/intel_8254_timer.cc b/src/dev/intel_8254_timer.cc
index b61aa7c56..9e507b968 100644
--- a/src/dev/intel_8254_timer.cc
+++ b/src/dev/intel_8254_timer.cc
@@ -32,7 +32,6 @@
 
 #include "base/misc.hh"
 #include "dev/intel_8254_timer.hh"
-#include "sim/sim_object.hh"
 
 using namespace std;
 
@@ -70,17 +69,6 @@ Intel8254Timer::writeControl(const CtrlReg data)
     }
 }
 
-unsigned int 
-Intel8254Timer::drain(Event *de)
-{
-    unsigned int count = 0;
-    count += counter[0]->drain(de);
-    count += counter[1]->drain(de);
-    count += counter[2]->drain(de);
-    assert(count == 0);
-    return count;
-}
-
 void
 Intel8254Timer::serialize(const string &base, ostream &os)
 {
@@ -228,18 +216,6 @@ Intel8254Timer::Counter::outputHigh()
     return output_high;
 }
 
-unsigned int 
-Intel8254Timer::Counter::drain(Event *de)
-{
-    if (event.scheduled()) {
-        event_tick = event.when();
-        parent->deschedule(event);
-    } else {
-        event_tick = 0;
-    }
-    return 0;
-}
-
 void
 Intel8254Timer::Counter::serialize(const string &base, ostream &os)
 {
@@ -251,6 +227,10 @@ Intel8254Timer::Counter::serialize(const string &base, ostream &os)
     paramOut(os, base + ".latch_on", latch_on);
     paramOut(os, base + ".read_byte", read_byte);
     paramOut(os, base + ".write_byte", write_byte);
+
+    Tick event_tick = 0;
+    if (event.scheduled())
+        event_tick = event.when();
     paramOut(os, base + ".event_tick", event_tick);
 }
 
@@ -267,6 +247,7 @@ Intel8254Timer::Counter::unserialize(const string &base, Checkpoint *cp,
     paramIn(cp, section, base + ".read_byte", read_byte);
     paramIn(cp, section, base + ".write_byte", write_byte);
 
+    Tick event_tick;
     paramIn(cp, section, base + ".event_tick", event_tick);
     if (event_tick)
         parent->schedule(event, event_tick);
diff --git a/src/dev/intel_8254_timer.hh b/src/dev/intel_8254_timer.hh
index 26ea0687e..30ddc7bca 100644
--- a/src/dev/intel_8254_timer.hh
+++ b/src/dev/intel_8254_timer.hh
@@ -137,10 +137,6 @@ class Intel8254Timer : public EventManager
         /** Pointer to container */
         Intel8254Timer *parent;
 
-        /** if non-zero, the scheduled tick of an event used for drain
-            serialization coordination */
-        Tick event_tick;
-
       public:
         Counter(Intel8254Timer *p, const std::string &name, unsigned int num);
 
@@ -169,12 +165,6 @@ class Intel8254Timer : public EventManager
         bool outputHigh();
 
         /**
-         * Drain all associated events.
-         * @param drainEvent
-         */
-        unsigned int drain(Event *de);
-
-        /**
          * Serialize this object to the given output stream.
          * @param base The base name of the counter object.
          * @param os   The stream to serialize to.
@@ -239,8 +229,6 @@ class Intel8254Timer : public EventManager
         return counter[num]->outputHigh();
     }
 
-    unsigned int drain(Event *de);
-
     /**
      * Serialize this object to the given output stream.
      * @param base The base name of the counter object.
diff --git a/src/dev/mc146818.cc b/src/dev/mc146818.cc
index fd70b503b..16ed58e46 100644
--- a/src/dev/mc146818.cc
+++ b/src/dev/mc146818.cc
@@ -40,7 +40,6 @@
 #include "base/trace.hh"
 #include "dev/mc146818.hh"
 #include "dev/rtcreg.h"
-#include "sim/sim_object.hh"
 
 using namespace std;
 
@@ -106,12 +105,8 @@ MC146818::MC146818(EventManager *em, const string &n, const struct tm time,
 
 MC146818::~MC146818()
 {
-    if (tickEvent.scheduled()) {
-        deschedule(tickEvent);
-    }
-    if (event.scheduled()) {
-        deschedule(event);
-    }
+    deschedule(tickEvent);
+    deschedule(event);
 }
 
 void
@@ -208,20 +203,6 @@ MC146818::tickClock()
     setTime(*gmtime(&calTime));
 }
 
-unsigned int 
-MC146818::drain(Event *de)
-{
-    if (event.scheduled()) {
-        rtcTimerInterruptTickOffset = event.when() - curTick;
-        rtcClockTickOffset = event.when() - curTick;
-        deschedule(event);
-    }
-    if (tickEvent.scheduled()) {
-        deschedule(tickEvent);
-    }
-    return 0;
-}
-
 void
 MC146818::serialize(const string &base, ostream &os)
 {
@@ -233,7 +214,9 @@ MC146818::serialize(const string &base, ostream &os)
     // save the timer tick and rtc clock tick values to correctly reschedule 
     // them during unserialize
     //
+    Tick rtcTimerInterruptTickOffset = event.when() - curTick;
     SERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
+    Tick rtcClockTickOffset = event.when() - curTick;
     SERIALIZE_SCALAR(rtcClockTickOffset);
 }
 
diff --git a/src/dev/mc146818.hh b/src/dev/mc146818.hh
index 507abab5a..699785199 100644
--- a/src/dev/mc146818.hh
+++ b/src/dev/mc146818.hh
@@ -119,10 +119,6 @@ class MC146818 : public EventManager
     /** RTC status register B */
     uint8_t stat_regB;
 
-    /** RTC event times for drain and serialization coordination */
-    Tick rtcTimerInterruptTickOffset;
-    Tick rtcClockTickOffset;
-
   public:
     MC146818(EventManager *em, const std::string &name, const struct tm time,
             bool bcd, Tick frequency);
@@ -136,8 +132,6 @@ class MC146818 : public EventManager
 
     void tickClock();
 
-    unsigned int drain(Event *de);
-
     /**
       * Serialize this object to the given output stream.
       * @param base The base name of the counter object.