On Wednesday, June 19, 2013 10:15:18 AM Shuah Khan wrote:
> pm_trace uses the system's Real Time Clock (RTC) to save the magic number.
> Reason for this is that the RTC is the only reliably available piece of
> hardware during resume operations where a value can be set that will
> survive a reboot.
>
> Consequence is that after a resume (even if it is successful) your system
> clock will have a value corresponding to the magic number instead of the
> correct date/time! It is therefore advisable to use a program like ntp-date
> or rdate to reset the correct date/time from an external time source when
> using this trace option.
>
> There is no run-time message to warn users of the consequences of enabling
> pm_trace. Adding a warning message to pm_trace_store() will serve as a
> reminder to users to set the system date and time after resume.
>
> Signed-off-by: Shuah Khan <shuah...@samsung.com>
> ---
> kernel/power/main.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/kernel/power/main.c b/kernel/power/main.c
> index d77663b..4f769a6 100644
> --- a/kernel/power/main.c
> +++ b/kernel/power/main.c
> @@ -528,6 +528,7 @@ pm_trace_store(struct kobject *kobj, struct
> kobj_attribute *attr,
>
> if (sscanf(buf, "%d", &val) == 1) {
> pm_trace_enabled = !!val;
> + pr_warn("CAUTION: this option will cause your machine's
> real-time clock to be set to an invalid time after a resume. Remember to set
> correct time after resume\n");
> return n;
Can you please make it short so that it fits a single line?
Or at least print two separate lines that will fit 80 chars wide screen each?
> }
> return -EINVAL;
>
Thanks,
Rafael
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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