From: Russell King <rmk+kernel@arm.linux.org.uk>
Date: Sat, 4 Feb 2012 12:31:27 +0000 (+0000)
Subject: ARM: sync sched_clock() state on suspend
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=f153d017ab70d2954f5456278f3cbc39e6e060f3;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

ARM: sync sched_clock() state on suspend

Ensure that the software state for sched_clock() is updated at the
point of suspend so that we avoid losing ticks since the last update.

This prevents the platform dependent possibility that sched_clock()
may appear to go backwards across a suspend/resume cycle.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---

diff --git a/arch/arm/kernel/sched_clock.c b/arch/arm/kernel/sched_clock.c
index 5416c7c12528..27d186abbc06 100644
--- a/arch/arm/kernel/sched_clock.c
+++ b/arch/arm/kernel/sched_clock.c
@@ -10,6 +10,7 @@
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/syscore_ops.h>
 #include <linux/timer.h>
 
 #include <asm/sched_clock.h>
@@ -164,3 +165,20 @@ void __init sched_clock_postinit(void)
 
 	sched_clock_poll(sched_clock_timer.data);
 }
+
+static int sched_clock_suspend(void)
+{
+	sched_clock_poll(sched_clock_timer.data);
+	return 0;
+}
+
+static struct syscore_ops sched_clock_ops = {
+	.suspend = sched_clock_suspend,
+};
+
+static int __init sched_clock_syscore_init(void)
+{
+	register_syscore_ops(&sched_clock_ops);
+	return 0;
+}
+device_initcall(sched_clock_syscore_init);