From 9081a9b2c3baee46b293b89dbce4b0045f3b846d Mon Sep 17 00:00:00 2001
From: Alexander Motin <mav@FreeBSD.org>
Date: Thu, 29 Sep 2011 14:19:34 +0000
Subject: [PATCH] Handle the race in cpu_idle() when due to the critical
 section CPU could get into sleep after receiving interrupt, delaying
 interrupt thread execution indefinitely until the next interrupt arrive.

Reviewed by:	nwhitehorn
MFC after:	3 days
---
 sys/powerpc/powerpc/cpu.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/powerpc/powerpc/cpu.c b/sys/powerpc/powerpc/cpu.c
index 97011562a8e..5d24eb160e7 100644
--- a/sys/powerpc/powerpc/cpu.c
+++ b/sys/powerpc/powerpc/cpu.c
@@ -553,6 +553,11 @@ cpu_idle_60x(void)
 	vers = mfpvr() >> 16;
 
 #ifdef AIM
+	mtmsr(msr & ~PSL_EE);
+	if (sched_runnable()) {
+		mtmsr(msr);
+		return;
+	}
 	switch (vers) {
 	case IBM970:
 	case IBM970FX:
@@ -583,6 +588,11 @@ cpu_idle_e500(void)
 	msr = mfmsr();
 
 #ifdef E500
+	mtmsr(msr & ~PSL_EE);
+	if (sched_runnable()) {
+		mtmsr(msr);
+		return;
+	}
 	/* Freescale E500 core RM section 6.4.1. */
 	__asm __volatile("msync; mtmsr %0; isync" ::
 	    "r" (msr | PSL_WE));