diff options
author | Brian Norris <computersforpeace@gmail.com> | 2015-02-22 21:16:49 -0800 |
---|---|---|
committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2015-02-26 01:21:26 +0100 |
commit | 1d4a9c17d4d204a159139361e8d4db7f9f267879 (patch) | |
tree | a419a5a715a3506e7972b556591b252f3b6ee10b /kernel/power/suspend.c | |
parent | c517d838eb7d07bbe9507871fab3931deccff539 (diff) | |
download | linux-1d4a9c17d4d204a159139361e8d4db7f9f267879.tar.gz |
PM / sleep: add configurable delay for pm_test
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> Reviewed-by: Kevin Cernekee <cernekee@chromium.org> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power/suspend.c')
-rw-r--r-- | kernel/power/suspend.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c index b7d6b3a721b1..8d7a1ef72758 100644 --- a/kernel/power/suspend.c +++ b/kernel/power/suspend.c @@ -28,6 +28,7 @@ #include <linux/ftrace.h> #include <trace/events/power.h> #include <linux/compiler.h> +#include <linux/moduleparam.h> #include "power.h" @@ -233,12 +234,20 @@ static bool platform_suspend_again(suspend_state_t state) suspend_ops->suspend_again() : false; } +#ifdef CONFIG_PM_DEBUG +static unsigned int pm_test_delay = 5; +module_param(pm_test_delay, uint, 0644); +MODULE_PARM_DESC(pm_test_delay, + "Number of seconds to wait before resuming from suspend test"); +#endif + static int suspend_test(int level) { #ifdef CONFIG_PM_DEBUG if (pm_test_level == level) { - printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n"); - mdelay(5000); + printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n", + pm_test_delay); + mdelay(pm_test_delay * 1000); return 1; } #endif /* !CONFIG_PM_DEBUG */ |