From mboxrd@z Thu Jan  1 00:00:00 1970
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Date: Tue, 31 Jul 2007 20:05:43 +0200
From: Jan Kiszka <jan.kiszka@domain.hid>
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Subject: [Xenomai-core] [PATCH] Revert broken edge_shirq optimisation
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To: Philippe Gerum <rpm@xenomai.org>
Cc: xenomai-core <xenomai@xenomai.org>

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Oh my dear. The ground may open and swallow me. This crappy piece of
optimisation in xnintr_edge_shirq_handler() I introduced both to 2.4 and
(sadly) the 2.3.x stable series cannot work. It must stay as it used to:

--- ksrc/nucleus/intr.c	(revision 2871)
+++ ksrc/nucleus/intr.c	(working copy)
@@ -296,15 +296,15 @@ static void xnintr_edge_shirq_handler(un
 		s |=3D ret;

 		if (code =3D=3D XN_ISR_HANDLED) {
-			if (!(end =3D (intr->next)))
-				end =3D shirq->handlers;
+			end =3D NULL;
 			xnstat_counter_inc(
 				&intr->stat[xnsched_cpu(sched)].hits);
 			xnstat_runtime_lazy_switch(sched,
 				&intr->stat[xnsched_cpu(sched)].account,
 				start);
 			start =3D xnstat_runtime_now();
-		}
+		} else if (code =3D=3D XN_ISR_NONE && end =3D=3D NULL)
+			end =3D intr;

 		if (counter++ > MAX_EDGEIRQ_COUNTER)
 			break;
(that's for 2.3.x)

Once "end" is moved forward to the next handler in the chain, the loop
termination condition "intr=3D=3Dend" will trigger on the immediately
following round, even if there are still events pending. Utterly broken.

Philippe, please quickly apply -- and don't tell anyone who did this.

Jan


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