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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-05-26 13:40:59 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-05-26 13:40:59 +0200
commit0399d4db3edf5c58b6ec7f672f089f5085e49ed5 (patch)
tree3948336693fa6a945cd54787b205cbcbcd8afa5d /kernel/power
parent43e8317b0bba1d6eb85f38a4a233d82d7c20d732 (diff)
downloadop-kernel-dev-0399d4db3edf5c58b6ec7f672f089f5085e49ed5.zip
op-kernel-dev-0399d4db3edf5c58b6ec7f672f089f5085e49ed5.tar.gz
PM / sleep: Introduce command line argument for sleep state enumeration
On some systems the platform doesn't support neither PM_SUSPEND_MEM nor PM_SUSPEND_STANDBY, so PM_SUSPEND_FREEZE is the only available system sleep state. However, some user space frameworks only use the "mem" and (sometimes) "standby" sleep state labels, so the users of those systems need to modify user space in order to be able to use system suspend at all and that is not always possible. For this reason, add a new kernel command line argument, relative_sleep_states, allowing the users of those systems to change the way in which the kernel assigns labels to system sleep states. Namely, for relative_sleep_states=1, the "mem", "standby" and "freeze" labels will enumerate the available system sleem states from the deepest to the shallowest, respectively, so that "mem" is always present in /sys/power/state and the other state strings may or may not be presend depending on what is supported by the platform. Update system sleep states documentation to reflect this change. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'kernel/power')
-rw-r--r--kernel/power/main.c12
-rw-r--r--kernel/power/suspend.c32
2 files changed, 36 insertions, 8 deletions
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 9f51f0a..573410d 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -279,14 +279,14 @@ static inline void pm_print_times_init(void) {}
struct kobject *power_kobj;
/**
- * state - control system power state.
+ * state - control system sleep states.
*
- * show() returns what states are supported, which is hard-coded to
- * 'freeze' (Low-Power Idle), 'standby' (Power-On Suspend),
- * 'mem' (Suspend-to-RAM), and 'disk' (Suspend-to-Disk).
+ * show() returns available sleep state labels, which may be "mem", "standby",
+ * "freeze" and "disk" (hibernation). See Documentation/power/states.txt for a
+ * description of what they mean.
*
- * store() accepts one of those strings, translates it into the
- * proper enumerated value, and initiates a suspend transition.
+ * store() accepts one of those strings, translates it into the proper
+ * enumerated value, and initiates a suspend transition.
*/
static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 00aca60..338a6f1 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -78,6 +78,26 @@ static bool valid_state(suspend_state_t state)
return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
}
+/*
+ * If this is set, the "mem" label always corresponds to the deepest sleep state
+ * available, the "standby" label corresponds to the second deepest sleep state
+ * available (if any), and the "freeze" label corresponds to the remaining
+ * available sleep state (if there is one).
+ */
+static bool relative_states;
+
+static int __init sleep_states_setup(char *str)
+{
+ relative_states = !strncmp(str, "1", 1);
+ if (relative_states) {
+ pm_states[PM_SUSPEND_MEM].state = PM_SUSPEND_FREEZE;
+ pm_states[PM_SUSPEND_FREEZE].state = 0;
+ }
+ return 1;
+}
+
+__setup("relative_sleep_states=", sleep_states_setup);
+
/**
* suspend_set_ops - Set the global suspend method table.
* @ops: Suspend operations to use.
@@ -85,12 +105,20 @@ static bool valid_state(suspend_state_t state)
void suspend_set_ops(const struct platform_suspend_ops *ops)
{
suspend_state_t i;
+ int j = PM_SUSPEND_MAX - 1;
lock_system_sleep();
suspend_ops = ops;
- for (i = PM_SUSPEND_STANDBY; i <= PM_SUSPEND_MEM; i++)
- pm_states[i].state = valid_state(i) ? i : 0;
+ for (i = PM_SUSPEND_MEM; i >= PM_SUSPEND_STANDBY; i--)
+ if (valid_state(i))
+ pm_states[j--].state = i;
+ else if (!relative_states)
+ pm_states[j--].state = 0;
+
+ pm_states[j--].state = PM_SUSPEND_FREEZE;
+ while (j >= PM_SUSPEND_MIN)
+ pm_states[j--].state = 0;
unlock_system_sleep();
}
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