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 @@ -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 *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;
