[PATCH 4.7 027/143] parisc: Fix automatic selection of cr16 clocksource
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2016-09-05 16:47:54
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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();