PM: base: power: don't try to use non-existing RTC for storing data

commit 0560204b360a332c321124dbc5cdfd3364533a74 upstream.

If there is no legacy RTC device, don't try to use it for storing trace
data across suspend/resume.

Cc: <stable@vger.kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Juergen Gross 2021-09-03 10:49:36 +02:00 committed by Greg Kroah-Hartman
parent a67e7cdbc6
commit cd64b416ae

View File

@ -13,6 +13,7 @@
#include <linux/export.h>
#include <linux/rtc.h>
#include <linux/suspend.h>
#include <linux/init.h>
#include <linux/mc146818rtc.h>
@ -165,6 +166,9 @@ 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);
@ -267,6 +271,9 @@ static struct notifier_block pm_trace_nb = {
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;
@ -277,6 +284,9 @@ 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;