From: Helge Deller <deller@gmx.de>
Date: Wed, 18 Oct 2017 20:25:00 +0000 (+0200)
Subject: parisc: Fix detection of nonsynchronous cr16 cycle counters
X-Git-Tag: v4.13.10~72
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d29babf5c2320f1e42fc4d343b3f369788696f23;p=thirdparty%2Fkernel%2Fstable.git

parisc: Fix detection of nonsynchronous cr16 cycle counters

commit 8642b31ba9eef8a01845146a26682d4869e62513 upstream.

For CPUs which have an unknown or invalid CPU location (physical location)
assume that their cycle counters aren't syncronized across CPUs.

Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: c8c3735997a3 ("parisc: Enhance detection of synchronous cr16 clocksources")
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/parisc/kernel/time.c b/arch/parisc/kernel/time.c
index 2d956aa0a38ab..8c0105a49839c 100644
--- a/arch/parisc/kernel/time.c
+++ b/arch/parisc/kernel/time.c
@@ -253,7 +253,10 @@ static int __init init_cr16_clocksource(void)
 		cpu0_loc = per_cpu(cpu_data, 0).cpu_loc;
 
 		for_each_online_cpu(cpu) {
-			if (cpu0_loc == per_cpu(cpu_data, cpu).cpu_loc)
+			if (cpu == 0)
+				continue;
+			if ((cpu0_loc != 0) &&
+			    (cpu0_loc == per_cpu(cpu_data, cpu).cpu_loc))
 				continue;
 
 			clocksource_cr16.name = "cr16_unstable";