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Commit 50990255 authored by Juergen Gross's avatar Juergen Gross Committed by Greg Kroah-Hartman
Browse files

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: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarRafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20210903084937.19392-2-jgross@suse.com


Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent aadf3115

drivers/base/power/trace.c

+10 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#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 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;