parisc: Fix automatic selection of cr16 clocksource

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>
Cc: stable@vger.kernel.org # 4.7+

diff --git a/arch/parisc/kernel/processor.c b/arch/parisc/kernel/processor.c
index 5adc339eb7c8dab935fbbc933a64e811f6800ccc..0c2a94a0f7518b8082ecda3f0307ead9534ea972 100644 (file)
--- 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_device *dev)
        }
 #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;
 }
 

diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c
index 505cf1ac5af24ecef4731f845fd6de516ae1f306..4b0b963d52a757e83674149f4162faf3eafb7456 100644 (file)
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -221,18 +221,6 @@ static struct clocksource clocksource_cr16 = {
        .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();