Messages in this thread | | | Date | Sun, 22 Feb 2015 13:27:54 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH v2] PM / sleep: add configurable delay for pm_test |
| |
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 <computersforpeace@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
(Does this need documentation in kernel-parameters.txt or in place where pm_test is documented?)
Thanks, Pavel
-- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
| |