From 62c552ccc3eda1198632a4f344aa32623d226bab Mon Sep 17 00:00:00 2001 From: Bojan Smojver Date: Sat, 16 Jun 2012 00:09:58 +0200 Subject: PM / Hibernate: Enable suspend to both for in-kernel hibernation. It is often useful to suspend to memory after hibernation image has been written to disk. If the battery runs out or power is otherwise lost, the computer will resume from the hibernated image. If not, it will resume from memory and hibernation image will be discarded. Signed-off-by: Bojan Smojver Signed-off-by: Rafael J. Wysocki --- Documentation/power/swsusp.txt | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'Documentation') diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt index ac190cf1963e..92341b84250d 100644 --- a/Documentation/power/swsusp.txt +++ b/Documentation/power/swsusp.txt @@ -33,6 +33,11 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state echo platform > /sys/power/disk; echo disk > /sys/power/state +. If you would like to write hibernation image to swap and then suspend +to RAM (provided your platform supports it), you can try + +echo suspend > /sys/power/disk; echo disk > /sys/power/state + . If you have SATA disks, you'll need recent kernels with SATA suspend support. For suspend and resume to work, make sure your disk drivers are built into kernel -- not modules. [There's way to make -- cgit v1.2.3 From 4b7760ba0dd3319f66886ab2335a0fbecdbc808a Mon Sep 17 00:00:00 2001 From: Sameer Nanda Date: Tue, 19 Jun 2012 22:23:33 +0200 Subject: PM / Sleep: add knob for printing device resume times Added a new knob called /sys/power/pm_print_times. Setting it to 1 enables printing of time taken by devices to suspend and resume. Setting it to 0 disables this printing (unless overridden by initcall_debug kernel command line option). Signed-off-by: Sameer Nanda Acked-by: Greg KH Signed-off-by: Rafael J. Wysocki --- Documentation/ABI/testing/sysfs-power | 13 +++++++++++++ drivers/base/power/main.c | 4 ++-- drivers/base/power/power.h | 11 +++++++++++ kernel/power/main.c | 33 +++++++++++++++++++++++++++++++++ 4 files changed, 59 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/ABI/testing/sysfs-power b/Documentation/ABI/testing/sysfs-power index 31725ffeeb3a..217772615d02 100644 --- a/Documentation/ABI/testing/sysfs-power +++ b/Documentation/ABI/testing/sysfs-power @@ -231,3 +231,16 @@ Description: Reads from this file return a string consisting of the names of wakeup sources created with the help of /sys/power/wake_lock that are inactive at the moment, separated with spaces. + +What: /sys/power/pm_print_times +Date: May 2012 +Contact: Sameer Nanda +Description: + The /sys/power/pm_print_times file allows user space to + control whether the time taken by devices to suspend and + resume is printed. These prints are useful for hunting down + devices that take too long to suspend or resume. + + Writing a "1" enables this printing while writing a "0" + disables it. The default value is "0". Reading from this file + will display the current value. diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index 9cb845e49334..6e4db96958d1 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -166,7 +166,7 @@ static ktime_t initcall_debug_start(struct device *dev) { ktime_t calltime = ktime_set(0, 0); - if (initcall_debug) { + if (pm_print_times) { pr_info("calling %s+ @ %i, parent: %s\n", dev_name(dev), task_pid_nr(current), dev->parent ? dev_name(dev->parent) : "none"); @@ -181,7 +181,7 @@ static void initcall_debug_report(struct device *dev, ktime_t calltime, { ktime_t delta, rettime; - if (initcall_debug) { + if (pm_print_times) { rettime = ktime_get(); delta = ktime_sub(rettime, calltime); pr_info("call %s+ returned %d after %Ld usecs\n", dev_name(dev), diff --git a/drivers/base/power/power.h b/drivers/base/power/power.h index eeb4bff9505c..12c77b7ff8e8 100644 --- a/drivers/base/power/power.h +++ b/drivers/base/power/power.h @@ -85,3 +85,14 @@ static inline int pm_qos_sysfs_add(struct device *dev) { return 0; } static inline void pm_qos_sysfs_remove(struct device *dev) {} #endif + +#ifdef CONFIG_PM_DEBUG + +extern int pm_print_times_enabled; +#define pm_print_times (initcall_debug || pm_print_times_enabled) + +#else /* CONFIG_PM_DEBUG */ + +#define pm_print_times initcall_debug + +#endif /* CONFIG_PM_DEBUG */ diff --git a/kernel/power/main.c b/kernel/power/main.c index 428f8a034e96..7beb3fb3670b 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -132,6 +132,38 @@ static ssize_t pm_test_store(struct kobject *kobj, struct kobj_attribute *attr, } power_attr(pm_test); + +/* + * pm_print_times: print time taken by devices to suspend and resume. + * + * show() returns whether printing of suspend and resume times is enabled. + * store() accepts 0 or 1. 0 disables printing and 1 enables it. + */ +int pm_print_times_enabled; + +static ssize_t pm_print_times_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + return sprintf(buf, "%d\n", pm_print_times_enabled); +} + +static ssize_t pm_print_times_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t n) +{ + unsigned long val; + + if (kstrtoul(buf, 10, &val)) + return -EINVAL; + + if (val > 1) + return -EINVAL; + + pm_print_times_enabled = val; + return n; +} + +power_attr(pm_print_times); #endif /* CONFIG_PM_DEBUG */ #ifdef CONFIG_DEBUG_FS @@ -530,6 +562,7 @@ static struct attribute * g[] = { #endif #ifdef CONFIG_PM_DEBUG &pm_test_attr.attr, + &pm_print_times_attr.attr, #endif #endif NULL, -- cgit v1.2.3 From 8d2c794108aed16602de1fcc37e485e9243ab5c0 Mon Sep 17 00:00:00 2001 From: Oskar Schirmer Date: Tue, 3 Jul 2012 09:27:24 +0000 Subject: PM / Documentation: fix typos in power management description Just two missing characters. Signed-off-by: Oskar Schirmer Signed-off-by: Rafael J. Wysocki --- Documentation/power/devices.txt | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index 872815cd41d3..504dfe4d52eb 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt @@ -583,9 +583,10 @@ for the given device during all power transitions, instead of the respective subsystem-level callbacks. Specifically, if a device's pm_domain pointer is not NULL, the ->suspend() callback from the object pointed to by it will be executed instead of its subsystem's (e.g. bus type's) ->suspend() callback and -anlogously for all of the remaining callbacks. In other words, power management -domain callbacks, if defined for the given device, always take precedence over -the callbacks provided by the device's subsystem (e.g. bus type). +analogously for all of the remaining callbacks. In other words, power +management domain callbacks, if defined for the given device, always take +precedence over the callbacks provided by the device's subsystem (e.g. bus +type). The support for device power management domains is only relevant to platforms needing to use the same device driver power management callbacks in many @@ -598,7 +599,7 @@ it into account in any way. Device Low Power (suspend) States --------------------------------- Device low-power states aren't standard. One device might only handle -"on" and "off, while another might support a dozen different versions of +"on" and "off", while another might support a dozen different versions of "on" (how many engines are active?), plus a state that gets back to "on" faster than from a full "off". -- cgit v1.2.3