On Sun, Feb 22, 2015 at 4:27 AM, Pavel Machek <pa...@ucw.cz> wrote: > On Sun 2015-02-22 00:26:54, Brian Norris wrote: >> When CONFIG_PM_DEBUG=y, we provide a sysfs file (/sys/power/pm_test) for >> selecting one of a few suspend test modes, where rather than entering a >> full suspend state, the kernel will perform some subset of suspend >> steps, wait 5 seconds, and then resume back to normal operation. >> >> This mode is useful for (among other things) observing the state of the >> system just before entering a sleep mode, for debugging or analysis >> purposes. However, a constant 5 second wait is not sufficient for some >> sorts of analysis; for example, on an SoC, one might want to use >> external tools to probe the power states of various on-chip controllers >> or clocks. >> >> This patch turns this 5 second delay into a configurable module >> parameter, so users can determine how long to wait in this >> pseudo-suspend state before resuming the system. >> >> Example (wait 30 seconds); >> >> # echo 30 > /sys/module/suspend/parameters/pm_test_delay >> # echo core > /sys/power/pm_test >> # time echo mem > /sys/power/state >> ... >> [ 17.583625] suspend debug: Waiting for 30 second(s). >> ... >> real 0m30.381s >> user 0m0.017s >> sys 0m0.080s >> >> Signed-off-by: Brian Norris <computersforpe...@gmail.com> > > Acked-by: Pavel Machek <pa...@ucw.cz> > > (Does this need documentation in kernel-parameters.txt or in place > where pm_test is documented?)
Perhaps both places? Documentation/power/basic-pm-debugging.txt still has the "wait 5 seconds" verbiage. Beyond that, it looks good to me: Reviewed-by: Kevin Cernekee <cerne...@chromium.org> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
