This is a note to let you know that I've just added the patch titled
PM: base: power: don't try to use non-existing RTC for storing data
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pm-base-power-don-t-try-to-use-non-existing-rtc-for-storing-data.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0560204b360a332c321124dbc5cdfd3364533a74 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@xxxxxxxx>
Date: Fri, 3 Sep 2021 10:49:36 +0200
Subject: PM: base: power: don't try to use non-existing RTC for storing data
From: Juergen Gross <jgross@xxxxxxxx>
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@xxxxxxxxxxxxxxx>
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@xxxxxxxx
Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/base/power/trace.c | 10 ++++++++++
1 file changed, 10 insertions(+)
--- a/drivers/base/power/trace.c
+++ b/drivers/base/power/trace.c
@@ -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 *trace
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 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 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;
Patches currently in stable-queue which might be from jgross@xxxxxxxx are
queue-5.4/pm-base-power-don-t-try-to-use-non-existing-rtc-for-storing-data.patch
queue-5.4/xen-fix-setting-of-max_pfn-in-shared_info.patch
queue-5.4/xen-reset-legacy-rtc-flag-for-pv-domu.patch
