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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.c26
1 files changed, 20 insertions, 6 deletions
diff --git a/drivers/base/power/trace.c b/drivers/base/power/trace.c
index b11f47a1e819..d8da7195bb00 100644
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
/*
* drivers/base/power/trace.c
*
@@ -6,11 +7,13 @@
* Trace facility for suspend/resume problems, when none of the
* devices may be working.
*/
+#define pr_fmt(fmt) "PM: " fmt
#include <linux/pm-trace.h>
#include <linux/export.h>
#include <linux/rtc.h>
#include <linux/suspend.h>
+#include <linux/init.h>
#include <linux/mc146818rtc.h>
@@ -117,7 +120,11 @@ static unsigned int read_magic_time(void)
struct rtc_time time;
unsigned int val;
- mc146818_get_time(&time);
+ if (mc146818_get_time(&time, 1000) < 0) {
+ pr_err("Unable to read current time from RTC\n");
+ return 0;
+ }
+
pr_info("RTC time: %ptRt, date: %ptRd\n", &time, &time);
val = time.tm_year; /* 100 years */
if (val > 100)
@@ -163,6 +170,9 @@ void generate_pm_trace(const void *tracedata, unsigned int user)
const char *file = *(const char **)(tracedata + 2);
unsigned int user_hash_value, file_hash_value;
+ if (!x86_platform.legacy.rtc)
+ return;
+
user_hash_value = user % USERHASH;
file_hash_value = hash_string(lineno, file, FILEHASH);
set_magic_time(user_hash_value, file_hash_value, dev_hash_value);
@@ -228,10 +238,8 @@ int show_trace_dev_match(char *buf, size_t size)
unsigned int hash = hash_string(DEVSEED, dev_name(dev),
DEVHASH);
if (hash == value) {
- int len = snprintf(buf, size, "%s\n",
+ int len = scnprintf(buf, size, "%s\n",
dev_driver_string(dev));
- if (len > size)
- len = size;
buf += len;
ret += len;
size -= len;
@@ -263,18 +271,24 @@ static struct notifier_block pm_trace_nb = {
.notifier_call = pm_trace_notify,
};
-static int early_resume_init(void)
+static int __init early_resume_init(void)
{
+ if (!x86_platform.legacy.rtc)
+ return 0;
+
hash_value_early_read = read_magic_time();
register_pm_notifier(&pm_trace_nb);
return 0;
}
-static int late_resume_init(void)
+static int __init late_resume_init(void)
{
unsigned int val = hash_value_early_read;
unsigned int user, file, dev;
+ if (!x86_platform.legacy.rtc)
+ return 0;
+
user = val % USERHASH;
val = val / USERHASH;
file = val % FILEHASH;