[PATCH] ppc32: fix powersave with interrupts disabled

It looks like the problem has to do with entering the powersave routine 
with irqs disabled. Here is a patch that will only enter powersave if irqs 
are enabled.

Entering powersave on PPC while irqs are disabled causes a hang. Only 
enter powersave if irqs are disabled.

Signed-off-by: Brian Waite <redacted> 
Signed-off-by: Kumar Gala <redacted>

---
diff -Nru a/arch/ppc/kernel/idle.c b/arch/ppc/kernel/idle.c

--- a/arch/ppc/kernel/idle.c	2005-01-24 15:48:24 -06:00
+++ b/arch/ppc/kernel/idle.c	2005-01-24 15:48:24 -06:00

@@ -39,7 +39,7 @@
 	powersave = ppc_md.power_save;
 
 	if (!need_resched()) {
-		if (powersave != NULL)
+		if (powersave != NULL && !irqs_disabled())
 			powersave();
 		else {
 #ifdef CONFIG_SMP

On Mon, 2005-01-24 at 15:51 -0600, Kumar Gala wrote:

It looks like the problem has to do with entering the powersave routine 
with irqs disabled. Here is a patch that will only enter powersave if irqs 
are enabled.

Entering powersave on PPC while irqs are disabled causes a hang. Only 
enter powersave if irqs are disabled.

I have a different fix which is to re-enable them (basically to move the
local_irq_disable we do in #ifdef CONFIG_SMP above the whole block,
removing the #else case).

I'm waiting for Ingo's ack about what exact race he's trying to fix
though...

Ben.