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-rw-r--r--arch/mips/Kconfig1
-rw-r--r--arch/mips/kernel/csrc-r4k.c40
2 files changed, 41 insertions, 0 deletions
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 2747b1b2d435..f347312ecd74 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1108,6 +1108,7 @@ config CSRC_IOASIC
bool
config CSRC_R4K
+ select CLOCKSOURCE_WATCHDOG if CPU_FREQ
bool
config CSRC_SB1250
diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index 437dda64fd7a..edc4afc080fa 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -6,6 +6,7 @@
* Copyright (C) 2007 by Ralf Baechle
*/
#include <linux/clocksource.h>
+#include <linux/cpufreq.h>
#include <linux/init.h>
#include <linux/sched_clock.h>
@@ -65,6 +66,45 @@ static bool rdhwr_count_usable(void)
return false;
}
+#ifdef CONFIG_CPU_FREQ
+
+static bool __read_mostly r4k_clock_unstable;
+
+static void r4k_clocksource_unstable(char *reason)
+{
+ if (r4k_clock_unstable)
+ return;
+
+ r4k_clock_unstable = true;
+
+ pr_info("R4K timer is unstable due to %s\n", reason);
+
+ clocksource_mark_unstable(&clocksource_mips);
+}
+
+static int r4k_cpufreq_callback(struct notifier_block *nb,
+ unsigned long val, void *data)
+{
+ if (val == CPUFREQ_POSTCHANGE)
+ r4k_clocksource_unstable("CPU frequency change");
+
+ return 0;
+}
+
+static struct notifier_block r4k_cpufreq_notifier = {
+ .notifier_call = r4k_cpufreq_callback,
+};
+
+static int __init r4k_register_cpufreq_notifier(void)
+{
+ return cpufreq_register_notifier(&r4k_cpufreq_notifier,
+ CPUFREQ_TRANSITION_NOTIFIER);
+
+}
+core_initcall(r4k_register_cpufreq_notifier);
+
+#endif /* !CONFIG_CPU_FREQ */
+
int __init init_r4k_clocksource(void)
{
if (!cpu_has_counter || !mips_hpt_frequency)