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path: root/drivers/base/power/trace.c
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Diffstat (limited to 'drivers/base/power/trace.c')
-rw-r--r--drivers/base/power/trace.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
index efec10b49d59..1cda505d6a85 100644
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -10,6 +10,7 @@
#include <linux/pm-trace.h>
#include <linux/export.h>
#include <linux/rtc.h>
+#include <linux/suspend.h>
#include <linux/mc146818rtc.h>
@@ -74,6 +75,9 @@
#define DEVSEED (7919)
+bool pm_trace_rtc_abused __read_mostly;
+EXPORT_SYMBOL_GPL(pm_trace_rtc_abused);
+
static unsigned int dev_hash_value;
static int set_magic_time(unsigned int user, unsigned int file, unsigned int device)
@@ -104,6 +108,7 @@ static int set_magic_time(unsigned int user, unsigned int file, unsigned int dev
time.tm_min = (n % 20) * 3;
n /= 20;
mc146818_set_time(&time);
+ pm_trace_rtc_abused = true;
return n ? -1 : 0;
}
@@ -239,9 +244,31 @@ int show_trace_dev_match(char *buf, size_t size)
return ret;
}
+static int
+pm_trace_notify(struct notifier_block *nb, unsigned long mode, void *_unused)
+{
+ switch (mode) {
+ case PM_POST_HIBERNATION:
+ case PM_POST_SUSPEND:
+ if (pm_trace_rtc_abused) {
+ pm_trace_rtc_abused = false;
+ pr_warn("Possible incorrect RTC due to pm_trace, please use 'ntpdate' or 'rdate' to reset it.\n");
+ }
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static struct notifier_block pm_trace_nb = {
+ .notifier_call = pm_trace_notify,
+};
+
static int early_resume_init(void)
{
hash_value_early_read = read_magic_time();
+ register_pm_notifier(&pm_trace_nb);
return 0;
}