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Subject[PATCH 4.7 027/143] parisc: Fix automatic selection of cr16 clocksource
Date
4.7-stable review patch.  If anyone has any objections, please let me know.

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

From: Helge Deller <deller@gmx.de>

commit ae141830b118c3fb5b7eab6fa7c8ab7b7224b0a4 upstream.

Commit 54b66800907 (parisc: Add native high-resolution sched_clock()
implementation) added support to use the CPU-internal cr16 counters as reliable
clocksource with the help of HAVE_UNSTABLE_SCHED_CLOCK.

Sadly the commit missed to remove the hack which prevented cr16 to become the
default clocksource even on SMP systems.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/parisc/kernel/processor.c | 8 --------
arch/parisc/kernel/time.c | 12 ------------
2 files changed, 20 deletions(-)

--- a/arch/parisc/kernel/processor.c
+++ b/arch/parisc/kernel/processor.c
@@ -51,8 +51,6 @@ EXPORT_SYMBOL(_parisc_requires_coherency

DEFINE_PER_CPU(struct cpuinfo_parisc, cpu_data);

-extern int update_cr16_clocksource(void); /* from time.c */
-
/*
** PARISC CPU driver - claim "device" and initialize CPU data structures.
**
@@ -228,12 +226,6 @@ static int processor_probe(struct parisc
}
#endif

- /* If we've registered more than one cpu,
- * we'll use the jiffies clocksource since cr16
- * is not synchronized between CPUs.
- */
- update_cr16_clocksource();
-
return 0;
}

--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -220,18 +220,6 @@ static struct clocksource clocksource_cr
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};

-int update_cr16_clocksource(void)
-{
- /* since the cr16 cycle counters are not synchronized across CPUs,
- we'll check if we should switch to a safe clocksource: */
- if (clocksource_cr16.rating != 0 && num_online_cpus() > 1) {
- clocksource_change_rating(&clocksource_cr16, 0);
- return 1;
- }
-
- return 0;
-}
-
void __init start_cpu_itimer(void)
{
unsigned int cpu = smp_processor_id();

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