> diff --git a/Documentation/power/s2ram.txt b/Documentation/power/s2ram.txt
> index b05f512..2ebdc60 100644
> --- a/Documentation/power/s2ram.txt
> +++ b/Documentation/power/s2ram.txt
> @@ -54,3 +54,21 @@ used to run with "radeonfb" (it's an ATI Radeon mobility). It turns out
> that "radeonfb" simply cannot resume that device - it tries to set the
> PLL's, and it just _hangs_. Using the regular VGA console and letting X
> resume it instead works fine.
> +
> +NOTE
> +====
> +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 mumber 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.
> +
> +As the clock keeps ticking it is also essential that the reboot is done
> +quickly after the resume failure. The trace option does not use the seconds
> +or the low order bits of the minutes of the RTC, but a too long delay will
> +corrupt the magic value.
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to
majordomo@vger.kernel.org
> More majordomo info at
http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at
http://www.tux.org/lkml/