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Subject[PATCH V2 1/2] MIPS: smp: Make stop_this_cpu() actually stop the CPU
Date
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@chromium.org>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
---
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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