Hmm. this somehow did not make it to akpm and lkml when I posted it a
week ago.

Fix the issue that the timer sometimes will not fire if the scheduled
time has already expired. Plus some simplifications and style changes.

Signed-off-by: Christoph Lameter <[EMAIL PROTECTED]>
Signed-off-by: Dimitri Sivanich <[EMAIL PROTECTED]>

Index: linux-2.6.11/drivers/char/mmtimer.c
===================================================================
--- linux-2.6.11.orig/drivers/char/mmtimer.c    2005-03-01 23:38:13.000000000 
-0800
+++ linux-2.6.11/drivers/char/mmtimer.c 2005-03-09 09:48:40.000000000 -0800
@@ -71,11 +71,6 @@ static struct file_operations mmtimer_fo
 };

 /*
- * Comparators and their associated info.  Shub has
- * three comparison registers.
- */
-
-/*
  * We only have comparison registers RTC1-4 currently available per
  * node.  RTC0 is used by SAL.
  */
@@ -174,14 +169,10 @@ static void inline mmtimer_setup_int_2(u
  * This function must be called with interrupts disabled and preemption off
  * in order to insure that the setup succeeds in a deterministic time frame.
  * It will check if the interrupt setup succeeded.
- * mmtimer_setup will return the cycles that we were too late if the
- * initialization failed.
  */
 static int inline mmtimer_setup(int comparator, unsigned long expires)
 {

-       long diff;
-
        switch (comparator) {
        case 0:
                mmtimer_setup_int_0(expires);
@@ -194,17 +185,14 @@ static int inline mmtimer_setup(int comp
                break;
        }
        /* We might've missed our expiration time */
-        diff = rtc_time() - expires;
-       if (diff > 0) {
-               if (mmtimer_int_pending(comparator)) {
-                       /* We'll get an interrupt for this once we're done */
-                        return 0;
-               }
-               /* Looks like we missed it */
-               return diff;
-        }
+       if (rtc_time() < expires)
+               return 1;

-       return 0;
+       /*
+        * If an interrupt is already pending then its okay
+        * if not then we failed
+        */
+       return mmtimer_int_pending(comparator);
 }

 static int inline mmtimer_disable_int(long nasid, int comparator)
@@ -430,7 +418,7 @@ static int inline reschedule_periodic_ti
                if (n > 20)
                        return 1;

-       } while (mmtimer_setup(x->i, t->it_timer.expires));
+       } while (!mmtimer_setup(x->i, t->it_timer.expires));

        return 0;
 }
@@ -594,9 +582,15 @@ static int sgi_timer_set(struct k_itimer

        if (flags & TIMER_ABSTIME) {
                struct timespec n;
+               unsigned long now;

                getnstimeofday(&n);
-               when -= timespec_to_ns(n);
+               now = timespec_to_ns(n);
+               if (when > now)
+                       when -= now;
+               else
+                       /* Fire the timer immediately */
+                       when = 0;
        }

        /*
@@ -644,7 +638,7 @@ retry:
        timr->it_timer.expires = when;

        if (period == 0) {
-               if (mmtimer_setup(i, when)) {
+               if (!mmtimer_setup(i, when)) {
                        mmtimer_disable_int(-1, i);
                        posix_timer_event(timr, 0);
                        timr->it_timer.expires = 0;
-
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