[PATCH V2 1/2] MIPS: smp: Make stop_this_cpu() actually stop the CPU

[Andrew Bresticker]

Since cpu_wait() enables interrupts upon return, CPUs which have
entered stop_this_cpu() may still end up handling interrupts.
This can lead to the softlockup detector firing on a panic or
restart/poweroff/halt.  Just disable interrupts and spin to ensure
nothing else runs on the CPU once it has entered stop_this_cpu().

Signed-off-by: Andrew Bresticker <abrestic@xxxxxxxxxxxx>
Cc: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Maciej W. Rozycki <macro@xxxxxxxxxxxxxx>
---
New for v2.
---
 arch/mips/kernel/smp.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 1c0d8c5..5b020bd 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -176,10 +176,8 @@ static void stop_this_cpu(void *dummy)
 	 * Remove this CPU:
 	 */
 	set_cpu_online(smp_processor_id(), false);
-	for (;;) {
-		if (cpu_wait)
-			(*cpu_wait)();		/* Wait if available. */
-	}
+	local_irq_disable();
+	while (1);
 }
 
 void smp_send_stop(void)
-- 
2.2.0.rc0.207.ga3a616c

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