1 files changed, 34 insertions, 0 deletions

diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 105f8ffa66a8..9338f1ad6100 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -13,6 +13,7 @@
 #include <linux/device.h>
 #include <linux/smp.h>
 #include <linux/cpu.h>
+#include <linux/cpu_pm.h>
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
 #include <linux/of_irq.h>
@@ -475,6 +476,33 @@ static struct notifier_block arch_timer_cpu_nb = {
         .notifier_call = arch_timer_cpu_notify,
 };
 
+#ifdef CONFIG_CPU_PM
+static unsigned int saved_cntkctl;
+static int arch_timer_cpu_pm_notify(struct notifier_block *self,
+                                    unsigned long action, void *hcpu)
+{
+        if (action == CPU_PM_ENTER)
+                saved_cntkctl = arch_timer_get_cntkctl();
+        else if (action == CPU_PM_ENTER_FAILED || action == CPU_PM_EXIT)
+                arch_timer_set_cntkctl(saved_cntkctl);
+        return NOTIFY_OK;
+}
+
+static struct notifier_block arch_timer_cpu_pm_notifier = {
+        .notifier_call = arch_timer_cpu_pm_notify,
+};
+
+static int __init arch_timer_cpu_pm_init(void)
+{
+        return cpu_pm_register_notifier(&arch_timer_cpu_pm_notifier);
+}
+#else
+static int __init arch_timer_cpu_pm_init(void)
+{
+        return 0;
+}
+#endif
+
 static int __init arch_timer_register(void)
 {
         int err;
@@ -514,11 +542,17 @@ static int __init arch_timer_register(void)
         if (err)
                 goto out_free_irq;
 
+        err = arch_timer_cpu_pm_init();
+        if (err)
+                goto out_unreg_notify;
+
         /* Immediately configure the timer on the boot CPU */
         arch_timer_setup(this_cpu_ptr(arch_timer_evt));
 
         return 0;
 
+out_unreg_notify:
+        unregister_cpu_notifier(&arch_timer_cpu_nb);
 out_free_irq:
         if (arch_timer_use_virtual)
                 free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);