Patch "parisc: Fix automatic selection of cr16 clocksource" has been added to the 4.7-stable tree

Patch "parisc: Fix automatic selection of cr16 clocksource" has been added to the 4.7-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    parisc: Fix automatic selection of cr16 clocksource

to the 4.7-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     parisc-fix-automatic-selection-of-cr16-clocksource.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ae141830b118c3fb5b7eab6fa7c8ab7b7224b0a4 Mon Sep 17 00:00:00 2001
From: Helge Deller <deller@gmx.de>
Date: Fri, 19 Aug 2016 22:39:02 +0200
Subject: parisc: Fix automatic selection of cr16 clocksource

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();


Patches currently in stable-queue which might be from deller@gmx.de are

queue-4.7/parisc-fix-order-of-erefused-define-in-errno.h.patch
queue-4.7/parisc-fix-automatic-selection-of-cr16-clocksource.patch