On 19/06/07, Jan Kiszka <[EMAIL PROTECTED]> wrote:
> Dmitry Adamushko wrote:
> > On 19/06/07, Jan Kiszka <[EMAIL PROTECTED]> wrote:
> >> [EMAIL PROTECTED] wrote:
> >> > Hi,
> >> > running a simple test application which spawns a periodic task
> >> writing on a
> >> > serial interface
> >> > the system hangs performing the rt_dev_close.
> >> > The test program ran fine with xeno 2.2.6 with "Shared Interrupts"
> >> enabled,
> >> > so as with
> >> > xeno 2.3.1 with "Shared Interrupts" disabled. It fails with xeno
> >> 2.3.1 with
> >> > "Shared Interrupts" enabled, so the problem seems to be in the shared
> >> > interrupts handling area.
> >> > kernel is 2.6.20 adeos patched
> >> >
> >> > Any suggestion?
> >
> > Does the fix below eliminate the problem?
> >
> > The problem (allegedly) is cause by the following reinitialization at
> > the end of the loop:
> >
> > ...
> > if (!(intr = intr->next))
> > intr = shirq->handlers;
> > ...
> >
> > 'end' may point to some of the elements ... and shirq->handlers may
> > become NULL (all elements have been deleted)..
>
> Good catch.
>
> >
> > (white-space damaged version.. enclosed a normal one)
> >
> > --- ksrc/nucleus/intr.c-orig 2007-06-19 13:44:55.090623404 +0200
> > +++ ksrc/nucleus/intr.c 2007-06-19 13:45:53.867440067 +0200
> > @@ -273,7 +273,7 @@ static void xnintr_edge_shirq_handler(un
> > xnintr_shirq_lock(shirq);
> > intr = shirq->handlers;
> >
> > - while (intr != end) {
> > + while (intr && intr != end) {
> > int ret, code;
> >
> > xnstat_runtime_switch(sched,
> >
> >
>
> But your patch looks incomplete: What if someone removes "end" but
> leaves other handlers behind while we are looping? Neither intr would
> then become NULL nor would we hit the end again. This seems to be more
> tricky...
Yeah.. what's about smth like this? (quick approach: if not ok, will
have to elaborate it thoroughly :-)
--- ksrc/nucleus/intr.c-orig 2007-06-19 13:44:55.090623404 +0200
+++ ksrc/nucleus/intr.c 2007-06-19 14:38:36.073535255 +0200
@@ -259,7 +259,7 @@ static void xnintr_edge_shirq_handler(un
xnstat_runtime_t *prev;
xnticks_t start;
xnintr_shirq_t *shirq = &xnshirqs[irq];
- xnintr_t *intr, *end = NULL;
+ xnintr_t *intr, *end = NULL, *old_end = NULL;
int s = 0, counter = 0;
xnarch_memory_barrier();
@@ -273,7 +273,7 @@ static void xnintr_edge_shirq_handler(un
xnintr_shirq_lock(shirq);
intr = shirq->handlers;
- while (intr != end) {
+ while (intr && intr != end) {
int ret, code;
xnstat_runtime_switch(sched,
@@ -297,8 +297,14 @@ static void xnintr_edge_shirq_handler(un
if (counter++ > MAX_EDGEIRQ_COUNTER)
break;
- if (!(intr = intr->next))
+ if (!(intr = intr->next)) {
intr = shirq->handlers;
+
+ /* 'end' has been removed in the mean time. */
+ if (end && old_end == end)
+ intr = NULL;
+ old_end = end;
+ }
}
xnintr_shirq_unlock(shirq);
>
> Jan
>
--
Best regards,
Dmitry Adamushko
_______________________________________________
Xenomai-help mailing list
[email protected]
https://mail.gna.org/listinfo/xenomai-help
