[PATCH 4.8 022/140] parisc: Fix self-detected CPU stall warnings on Mako machines

From: Greg Kroah-Hartman
Date: Wed Oct 26 2016 - 09:33:29 EST


4.8-stable review patch. If anyone has any objections, please let me know.

------------------

From: Helge Deller <deller@xxxxxx>

commit 92420bd0d01f040bbf754e1d090be49ca6a1c8d6 upstream.

The config option HAVE_UNSTABLE_SCHED_CLOCK is set automatically when compiling
for SMP. There is no need to clear the stable-clock flag via
clear_sched_clock_stable() when starting secondary CPUs, and even worse,
clearing it triggers wrong self-detected CPU stall warnings on 64bit Mako
machines.

Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/parisc/kernel/time.c | 6 ------
1 file changed, 6 deletions(-)

--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -226,12 +226,6 @@ void __init start_cpu_itimer(void)
unsigned int cpu = smp_processor_id();
unsigned long next_tick = mfctl(16) + clocktick;

-#if defined(CONFIG_HAVE_UNSTABLE_SCHED_CLOCK) && defined(CONFIG_64BIT)
- /* With multiple 64bit CPUs online, the cr16's are not syncronized. */
- if (cpu != 0)
- clear_sched_clock_stable();
-#endif
-
mtctl(next_tick, 16); /* kick off Interval Timer (CR16) */

per_cpu(cpu_data, cpu).it_value = next_tick;