Tickless mode tentative fix: http://www.chibios.com/forum/viewtopic.php?f=35&t=3532

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@9854 35acf78f-673a-0410-8e92-d51de3d6d3f4

1 files changed, 20 insertions, 7 deletions

diff --git a/os/rt/src/chvt.c b/os/rt/src/chvt.c
index 965c79121..51db54cc3 100644
--- a/os/rt/src/chvt.c
+++ b/os/rt/src/chvt.c
@@ -131,23 +131,36 @@ void chVTDoSetI(virtual_timer_t *vtp, systime_t delay,
       return;

     }

 

-    /* Special case where the timer will be placed as first element in a

-       non-empty list, the alarm needs to be recalculated.*/

-    delta = now + delay - ch.vtlist.lasttime;

-    if (delta < ch.vtlist.next->delta) {

-

-      /* New alarm deadline.*/

+    /* Pointer to the first element in the delta list, which is non-empty.*/

+    p = ch.vtlist.next;

+

+    /* Delay as delta from 'lasttime'. Note, it can overflow and the value

+       becomes lower than 'now'.*/

+    delta = now - ch.vtlist.lasttime + delay;

+

+    if (delta < now - ch.vtlist.lasttime) {

+      /* Scenario where a very large delay excedeed the numeric range, it

+         requires a special handling. We need to skip the first element and

+         adjust the delta to wrap back in the previous numeric range.*/

+      delta -= p->delta;

+      p = p->next;

+    }

+    else if (delta < p->delta) {

+     /* A small delay that will become the first element in the delta list

+        and next deadline.*/

       port_timer_set_alarm(ch.vtlist.lasttime + delta);

     }

   }

 #else /* CH_CFG_ST_TIMEDELTA == 0 */

   /* Delta is initially equal to the specified delay.*/

   delta = delay;

+

+  /* Pointer to the first element in the delta list.*/

+  p = ch.vtlist.next;

 #endif /* CH_CFG_ST_TIMEDELTA == 0 */

 

   /* The delta list is scanned in order to find the correct position for

      this timer. */

-  p = ch.vtlist.next;

   while (p->delta < delta) {

     delta -= p->delta;

     p = p->next;