diff options
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/kernel-parameters.txt | 5 | ||||
-rw-r--r-- | Documentation/power/basic-pm-debugging.txt | 216 | ||||
-rw-r--r-- | Documentation/power/devices.txt | 49 | ||||
-rw-r--r-- | Documentation/power/drivers-testing.txt | 30 | ||||
-rw-r--r-- | Documentation/power/notifiers.txt | 8 | ||||
-rw-r--r-- | Documentation/power/userland-swsusp.txt | 82 |
6 files changed, 216 insertions, 174 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 92c40d174355..cf3868956f1e 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt | |||
@@ -168,6 +168,11 @@ and is between 256 and 4096 characters. It is defined in the file | |||
168 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA | 168 | acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA |
169 | Format: <irq>,<irq>... | 169 | Format: <irq>,<irq>... |
170 | 170 | ||
171 | acpi_new_pts_ordering [HW,ACPI] | ||
172 | Enforce the ACPI 2.0 ordering of the _PTS control | ||
173 | method wrt putting devices into low power states | ||
174 | default: pre ACPI 2.0 ordering of _PTS | ||
175 | |||
171 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT | 176 | acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT |
172 | 177 | ||
173 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS | 178 | acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS |
diff --git a/Documentation/power/basic-pm-debugging.txt b/Documentation/power/basic-pm-debugging.txt index 57aef2f6e0de..1555001bc733 100644 --- a/Documentation/power/basic-pm-debugging.txt +++ b/Documentation/power/basic-pm-debugging.txt | |||
@@ -1,45 +1,111 @@ | |||
1 | Debugging suspend and resume | 1 | Debugging hibernation and suspend |
2 | (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL | 2 | (C) 2007 Rafael J. Wysocki <rjw@sisk.pl>, GPL |
3 | 3 | ||
4 | 1. Testing suspend to disk (STD) | 4 | 1. Testing hibernation (aka suspend to disk or STD) |
5 | 5 | ||
6 | To verify that the STD works, you can try to suspend in the "reboot" mode: | 6 | To check if hibernation works, you can try to hibernate in the "reboot" mode: |
7 | 7 | ||
8 | # echo reboot > /sys/power/disk | 8 | # echo reboot > /sys/power/disk |
9 | # echo disk > /sys/power/state | 9 | # echo disk > /sys/power/state |
10 | 10 | ||
11 | and the system should suspend, reboot, resume and get back to the command prompt | 11 | and the system should create a hibernation image, reboot, resume and get back to |
12 | where you have started the transition. If that happens, the STD is most likely | 12 | the command prompt where you have started the transition. If that happens, |
13 | to work correctly, but you need to repeat the test at least a couple of times in | 13 | hibernation is most likely to work correctly. Still, you need to repeat the |
14 | a row for confidence. This is necessary, because some problems only show up on | 14 | test at least a couple of times in a row for confidence. [This is necessary, |
15 | a second attempt at suspending and resuming the system. You should also test | 15 | because some problems only show up on a second attempt at suspending and |
16 | the "platform" and "shutdown" modes of suspend: | 16 | resuming the system.] Moreover, hibernating in the "reboot" and "shutdown" |
17 | modes causes the PM core to skip some platform-related callbacks which on ACPI | ||
18 | systems might be necessary to make hibernation work. Thus, if you machine fails | ||
19 | to hibernate or resume in the "reboot" mode, you should try the "platform" mode: | ||
17 | 20 | ||
18 | # echo platform > /sys/power/disk | 21 | # echo platform > /sys/power/disk |
19 | # echo disk > /sys/power/state | 22 | # echo disk > /sys/power/state |
20 | 23 | ||
21 | or | 24 | which is the default and recommended mode of hibernation. |
25 | |||
26 | Unfortunately, the "platform" mode of hibernation does not work on some systems | ||
27 | with broken BIOSes. In such cases the "shutdown" mode of hibernation might | ||
28 | work: | ||
22 | 29 | ||
23 | # echo shutdown > /sys/power/disk | 30 | # echo shutdown > /sys/power/disk |
24 | # echo disk > /sys/power/state | 31 | # echo disk > /sys/power/state |
25 | 32 | ||
26 | in which cases you will have to press the power button to make the system | 33 | (it is similar to the "reboot" mode, but it requires you to press the power |
27 | resume. If that does not work, you will need to identify what goes wrong. | 34 | button to make the system resume). |
35 | |||
36 | If neither "platform" nor "shutdown" hibernation mode works, you will need to | ||
37 | identify what goes wrong. | ||
38 | |||
39 | a) Test modes of hibernation | ||
40 | |||
41 | To find out why hibernation fails on your system, you can use a special testing | ||
42 | facility available if the kernel is compiled with CONFIG_PM_DEBUG set. Then, | ||
43 | there is the file /sys/power/pm_test that can be used to make the hibernation | ||
44 | core run in a test mode. There are 5 test modes available: | ||
45 | |||
46 | freezer | ||
47 | - test the freezing of processes | ||
48 | |||
49 | devices | ||
50 | - test the freezing of processes and suspending of devices | ||
28 | 51 | ||
29 | a) Test mode of STD | 52 | platform |
53 | - test the freezing of processes, suspending of devices and platform | ||
54 | global control methods(*) | ||
30 | 55 | ||
31 | To verify if there are any drivers that cause problems you can run the STD | 56 | processors |
32 | in the test mode: | 57 | - test the freezing of processes, suspending of devices, platform |
58 | global control methods(*) and the disabling of nonboot CPUs | ||
33 | 59 | ||
34 | # echo test > /sys/power/disk | 60 | core |
61 | - test the freezing of processes, suspending of devices, platform global | ||
62 | control methods(*), the disabling of nonboot CPUs and suspending of | ||
63 | platform/system devices | ||
64 | |||
65 | (*) the platform global control methods are only available on ACPI systems | ||
66 | and are only tested if the hibernation mode is set to "platform" | ||
67 | |||
68 | To use one of them it is necessary to write the corresponding string to | ||
69 | /sys/power/pm_test (eg. "devices" to test the freezing of processes and | ||
70 | suspending devices) and issue the standard hibernation commands. For example, | ||
71 | to use the "devices" test mode along with the "platform" mode of hibernation, | ||
72 | you should do the following: | ||
73 | |||
74 | # echo devices > /sys/power/pm_test | ||
75 | # echo platform > /sys/power/disk | ||
35 | # echo disk > /sys/power/state | 76 | # echo disk > /sys/power/state |
36 | 77 | ||
37 | in which case the system should freeze tasks, suspend devices, disable nonboot | 78 | Then, the kernel will try to freeze processes, suspend devices, wait 5 seconds, |
38 | CPUs (if any), wait for 5 seconds, enable nonboot CPUs, resume devices, thaw | 79 | resume devices and thaw processes. If "platform" is written to |
39 | tasks and return to your command prompt. If that fails, most likely there is | 80 | /sys/power/pm_test , then after suspending devices the kernel will additionally |
40 | a driver that fails to either suspend or resume (in the latter case the system | 81 | invoke the global control methods (eg. ACPI global control methods) used to |
41 | may hang or be unstable after the test, so please take that into consideration). | 82 | prepare the platform firmware for hibernation. Next, it will wait 5 seconds and |
42 | To find this driver, you can carry out a binary search according to the rules: | 83 | invoke the platform (eg. ACPI) global methods used to cancel hibernation etc. |
84 | |||
85 | Writing "none" to /sys/power/pm_test causes the kernel to switch to the normal | ||
86 | hibernation/suspend operations. Also, when open for reading, /sys/power/pm_test | ||
87 | contains a space-separated list of all available tests (including "none" that | ||
88 | represents the normal functionality) in which the current test level is | ||
89 | indicated by square brackets. | ||
90 | |||
91 | Generally, as you can see, each test level is more "invasive" than the previous | ||
92 | one and the "core" level tests the hardware and drivers as deeply as possible | ||
93 | without creating a hibernation image. Obviously, if the "devices" test fails, | ||
94 | the "platform" test will fail as well and so on. Thus, as a rule of thumb, you | ||
95 | should try the test modes starting from "freezer", through "devices", "platform" | ||
96 | and "processors" up to "core" (repeat the test on each level a couple of times | ||
97 | to make sure that any random factors are avoided). | ||
98 | |||
99 | If the "freezer" test fails, there is a task that cannot be frozen (in that case | ||
100 | it usually is possible to identify the offending task by analysing the output of | ||
101 | dmesg obtained after the failing test). Failure at this level usually means | ||
102 | that there is a problem with the tasks freezer subsystem that should be | ||
103 | reported. | ||
104 | |||
105 | If the "devices" test fails, most likely there is a driver that cannot suspend | ||
106 | or resume its device (in the latter case the system may hang or become unstable | ||
107 | after the test, so please take that into consideration). To find this driver, | ||
108 | you can carry out a binary search according to the rules: | ||
43 | - if the test fails, unload a half of the drivers currently loaded and repeat | 109 | - if the test fails, unload a half of the drivers currently loaded and repeat |
44 | (that would probably involve rebooting the system, so always note what drivers | 110 | (that would probably involve rebooting the system, so always note what drivers |
45 | have been loaded before the test), | 111 | have been loaded before the test), |
@@ -47,23 +113,46 @@ have been loaded before the test), | |||
47 | recently and repeat. | 113 | recently and repeat. |
48 | 114 | ||
49 | Once you have found the failing driver (there can be more than just one of | 115 | Once you have found the failing driver (there can be more than just one of |
50 | them), you have to unload it every time before the STD transition. In that case | 116 | them), you have to unload it every time before hibernation. In that case please |
51 | please make sure to report the problem with the driver. | 117 | make sure to report the problem with the driver. |
52 | 118 | ||
53 | It is also possible that a cycle can still fail after you have unloaded | 119 | It is also possible that the "devices" test will still fail after you have |
54 | all modules. In that case, you would want to look in your kernel configuration | 120 | unloaded all modules. In that case, you may want to look in your kernel |
55 | for the drivers that can be compiled as modules (testing again with them as | 121 | configuration for the drivers that can be compiled as modules (and test again |
56 | modules), and possibly also try boot time options such as "noapic" or "noacpi". | 122 | with these drivers compiled as modules). You may also try to use some special |
123 | kernel command line options such as "noapic", "noacpi" or even "acpi=off". | ||
124 | |||
125 | If the "platform" test fails, there is a problem with the handling of the | ||
126 | platform (eg. ACPI) firmware on your system. In that case the "platform" mode | ||
127 | of hibernation is not likely to work. You can try the "shutdown" mode, but that | ||
128 | is rather a poor man's workaround. | ||
129 | |||
130 | If the "processors" test fails, the disabling/enabling of nonboot CPUs does not | ||
131 | work (of course, this only may be an issue on SMP systems) and the problem | ||
132 | should be reported. In that case you can also try to switch the nonboot CPUs | ||
133 | off and on using the /sys/devices/system/cpu/cpu*/online sysfs attributes and | ||
134 | see if that works. | ||
135 | |||
136 | If the "core" test fails, which means that suspending of the system/platform | ||
137 | devices has failed (these devices are suspended on one CPU with interrupts off), | ||
138 | the problem is most probably hardware-related and serious, so it should be | ||
139 | reported. | ||
140 | |||
141 | A failure of any of the "platform", "processors" or "core" tests may cause your | ||
142 | system to hang or become unstable, so please beware. Such a failure usually | ||
143 | indicates a serious problem that very well may be related to the hardware, but | ||
144 | please report it anyway. | ||
57 | 145 | ||
58 | b) Testing minimal configuration | 146 | b) Testing minimal configuration |
59 | 147 | ||
60 | If the test mode of STD works, you can boot the system with "init=/bin/bash" | 148 | If all of the hibernation test modes work, you can boot the system with the |
61 | and attempt to suspend in the "reboot", "shutdown" and "platform" modes. If | 149 | "init=/bin/bash" command line parameter and attempt to hibernate in the |
62 | that does not work, there probably is a problem with a driver statically | 150 | "reboot", "shutdown" and "platform" modes. If that does not work, there |
63 | compiled into the kernel and you can try to compile more drivers as modules, | 151 | probably is a problem with a driver statically compiled into the kernel and you |
64 | so that they can be tested individually. Otherwise, there is a problem with a | 152 | can try to compile more drivers as modules, so that they can be tested |
65 | modular driver and you can find it by loading a half of the modules you normally | 153 | individually. Otherwise, there is a problem with a modular driver and you can |
66 | use and binary searching in accordance with the algorithm: | 154 | find it by loading a half of the modules you normally use and binary searching |
155 | in accordance with the algorithm: | ||
67 | - if there are n modules loaded and the attempt to suspend and resume fails, | 156 | - if there are n modules loaded and the attempt to suspend and resume fails, |
68 | unload n/2 of the modules and try again (that would probably involve rebooting | 157 | unload n/2 of the modules and try again (that would probably involve rebooting |
69 | the system), | 158 | the system), |
@@ -71,19 +160,19 @@ the system), | |||
71 | load n/2 modules more and try again. | 160 | load n/2 modules more and try again. |
72 | 161 | ||
73 | Again, if you find the offending module(s), it(they) must be unloaded every time | 162 | Again, if you find the offending module(s), it(they) must be unloaded every time |
74 | before the STD transition, and please report the problem with it(them). | 163 | before hibernation, and please report the problem with it(them). |
75 | 164 | ||
76 | c) Advanced debugging | 165 | c) Advanced debugging |
77 | 166 | ||
78 | In case the STD does not work on your system even in the minimal configuration | 167 | In case that hibernation does not work on your system even in the minimal |
79 | and compiling more drivers as modules is not practical or some modules cannot | 168 | configuration and compiling more drivers as modules is not practical or some |
80 | be unloaded, you can use one of the more advanced debugging techniques to find | 169 | modules cannot be unloaded, you can use one of the more advanced debugging |
81 | the problem. First, if there is a serial port in your box, you can boot the | 170 | techniques to find the problem. First, if there is a serial port in your box, |
82 | kernel with the 'no_console_suspend' parameter and try to log kernel | 171 | you can boot the kernel with the 'no_console_suspend' parameter and try to log |
83 | messages using the serial console. This may provide you with some information | 172 | kernel messages using the serial console. This may provide you with some |
84 | about the reasons of the suspend (resume) failure. Alternatively, it may be | 173 | information about the reasons of the suspend (resume) failure. Alternatively, |
85 | possible to use a FireWire port for debugging with firescope | 174 | it may be possible to use a FireWire port for debugging with firescope |
86 | (ftp://ftp.firstfloor.org/pub/ak/firescope/). On i386 it is also possible to | 175 | (ftp://ftp.firstfloor.org/pub/ak/firescope/). On x86 it is also possible to |
87 | use the PM_TRACE mechanism documented in Documentation/s2ram.txt . | 176 | use the PM_TRACE mechanism documented in Documentation/s2ram.txt . |
88 | 177 | ||
89 | 2. Testing suspend to RAM (STR) | 178 | 2. Testing suspend to RAM (STR) |
@@ -91,16 +180,25 @@ use the PM_TRACE mechanism documented in Documentation/s2ram.txt . | |||
91 | To verify that the STR works, it is generally more convenient to use the s2ram | 180 | To verify that the STR works, it is generally more convenient to use the s2ram |
92 | tool available from http://suspend.sf.net and documented at | 181 | tool available from http://suspend.sf.net and documented at |
93 | http://en.opensuse.org/s2ram . However, before doing that it is recommended to | 182 | http://en.opensuse.org/s2ram . However, before doing that it is recommended to |
94 | carry out the procedure described in section 1. | 183 | carry out STR testing using the facility described in section 1. |
95 | 184 | ||
96 | Assume you have resolved the problems with the STD and you have found some | 185 | Namely, after writing "freezer", "devices", "platform", "processors", or "core" |
97 | failing drivers. These drivers are also likely to fail during the STR or | 186 | into /sys/power/pm_test (available if the kernel is compiled with |
98 | during the resume, so it is better to unload them every time before the STR | 187 | CONFIG_PM_DEBUG set) the suspend code will work in the test mode corresponding |
99 | transition. Now, you can follow the instructions at | 188 | to given string. The STR test modes are defined in the same way as for |
100 | http://en.opensuse.org/s2ram to test the system, but if it does not work | 189 | hibernation, so please refer to Section 1 for more information about them. In |
101 | "out of the box", you may need to boot it with "init=/bin/bash" and test | 190 | particular, the "core" test allows you to test everything except for the actual |
102 | s2ram in the minimal configuration. In that case, you may be able to search | 191 | invocation of the platform firmware in order to put the system into the sleep |
103 | for failing drivers by following the procedure analogous to the one described in | 192 | state. |
104 | 1b). If you find some failing drivers, you will have to unload them every time | 193 | |
105 | before the STR transition (ie. before you run s2ram), and please report the | 194 | Among other things, the testing with the help of /sys/power/pm_test may allow |
106 | problems with them. | 195 | you to identify drivers that fail to suspend or resume their devices. They |
196 | should be unloaded every time before an STR transition. | ||
197 | |||
198 | Next, you can follow the instructions at http://en.opensuse.org/s2ram to test | ||
199 | the system, but if it does not work "out of the box", you may need to boot it | ||
200 | with "init=/bin/bash" and test s2ram in the minimal configuration. In that | ||
201 | case, you may be able to search for failing drivers by following the procedure | ||
202 | analogous to the one described in section 1. If you find some failing drivers, | ||
203 | you will have to unload them every time before an STR transition (ie. before | ||
204 | you run s2ram), and please report the problems with them. | ||
diff --git a/Documentation/power/devices.txt b/Documentation/power/devices.txt index d0e79d5820a5..c53d26361919 100644 --- a/Documentation/power/devices.txt +++ b/Documentation/power/devices.txt | |||
@@ -502,52 +502,3 @@ If the CPU can have a "cpufreq" driver, there also may be opportunities | |||
502 | to shift to lower voltage settings and reduce the power cost of executing | 502 | to shift to lower voltage settings and reduce the power cost of executing |
503 | a given number of instructions. (Without voltage adjustment, it's rare | 503 | a given number of instructions. (Without voltage adjustment, it's rare |
504 | for cpufreq to save much power; the cost-per-instruction must go down.) | 504 | for cpufreq to save much power; the cost-per-instruction must go down.) |
505 | |||
506 | |||
507 | /sys/devices/.../power/state files | ||
508 | ================================== | ||
509 | For now you can also test some of this functionality using sysfs. | ||
510 | |||
511 | DEPRECATED: USE "power/state" ONLY FOR DRIVER TESTING, AND | ||
512 | AVOID USING dev->power.power_state IN DRIVERS. | ||
513 | |||
514 | THESE WILL BE REMOVED. IF THE "power/state" FILE GETS REPLACED, | ||
515 | IT WILL BECOME SOMETHING COUPLED TO THE BUS OR DRIVER. | ||
516 | |||
517 | In each device's directory, there is a 'power' directory, which contains | ||
518 | at least a 'state' file. The value of this field is effectively boolean, | ||
519 | PM_EVENT_ON or PM_EVENT_SUSPEND. | ||
520 | |||
521 | * Reading from this file displays a value corresponding to | ||
522 | the power.power_state.event field. All nonzero values are | ||
523 | displayed as "2", corresponding to a low power state; zero | ||
524 | is displayed as "0", corresponding to normal operation. | ||
525 | |||
526 | * Writing to this file initiates a transition using the | ||
527 | specified event code number; only '0', '2', and '3' are | ||
528 | accepted (without a newline); '2' and '3' are both | ||
529 | mapped to PM_EVENT_SUSPEND. | ||
530 | |||
531 | On writes, the PM core relies on that recorded event code and the device/bus | ||
532 | capabilities to determine whether it uses a partial suspend() or resume() | ||
533 | sequence to change things so that the recorded event corresponds to the | ||
534 | numeric parameter. | ||
535 | |||
536 | - If the bus requires the irqs-disabled suspend_late()/resume_early() | ||
537 | phases, writes fail because those operations are not supported here. | ||
538 | |||
539 | - If the recorded value is the expected value, nothing is done. | ||
540 | |||
541 | - If the recorded value is nonzero, the device is partially resumed, | ||
542 | using the bus.resume() and/or class.resume() methods. | ||
543 | |||
544 | - If the target value is nonzero, the device is partially suspended, | ||
545 | using the class.suspend() and/or bus.suspend() methods and the | ||
546 | PM_EVENT_SUSPEND message. | ||
547 | |||
548 | Drivers have no way to tell whether their suspend() and resume() calls | ||
549 | have come through the sysfs power/state file or as part of entering a | ||
550 | system sleep state, except that when accessed through sysfs the normal | ||
551 | parent/child sequencing rules are ignored. Drivers (such as bus, bridge, | ||
552 | or hub drivers) which expose child devices may need to enforce those rules | ||
553 | on their own. | ||
diff --git a/Documentation/power/drivers-testing.txt b/Documentation/power/drivers-testing.txt index e4bdcaee24e4..7f7a737f7f9f 100644 --- a/Documentation/power/drivers-testing.txt +++ b/Documentation/power/drivers-testing.txt | |||
@@ -6,9 +6,9 @@ Testing suspend and resume support in device drivers | |||
6 | Unfortunately, to effectively test the support for the system-wide suspend and | 6 | Unfortunately, to effectively test the support for the system-wide suspend and |
7 | resume transitions in a driver, it is necessary to suspend and resume a fully | 7 | resume transitions in a driver, it is necessary to suspend and resume a fully |
8 | functional system with this driver loaded. Moreover, that should be done | 8 | functional system with this driver loaded. Moreover, that should be done |
9 | several times, preferably several times in a row, and separately for the suspend | 9 | several times, preferably several times in a row, and separately for hibernation |
10 | to disk (STD) and the suspend to RAM (STR) transitions, because each of these | 10 | (aka suspend to disk or STD) and suspend to RAM (STR), because each of these |
11 | cases involves different ordering of operations and different interactions with | 11 | cases involves slightly different operations and different interactions with |
12 | the machine's BIOS. | 12 | the machine's BIOS. |
13 | 13 | ||
14 | Of course, for this purpose the test system has to be known to suspend and | 14 | Of course, for this purpose the test system has to be known to suspend and |
@@ -22,20 +22,24 @@ for more information about the debugging of suspend/resume functionality. | |||
22 | Once you have resolved the suspend/resume-related problems with your test system | 22 | Once you have resolved the suspend/resume-related problems with your test system |
23 | without the new driver, you are ready to test it: | 23 | without the new driver, you are ready to test it: |
24 | 24 | ||
25 | a) Build the driver as a module, load it and try the STD in the test mode (see: | 25 | a) Build the driver as a module, load it and try the test modes of hibernation |
26 | Documents/power/basic-pm-debugging.txt, 1a)). | 26 | (see: Documents/power/basic-pm-debugging.txt, 1). |
27 | 27 | ||
28 | b) Load the driver and attempt to suspend to disk in the "reboot", "shutdown" | 28 | b) Load the driver and attempt to hibernate in the "reboot", "shutdown" and |
29 | and "platform" modes (see: Documents/power/basic-pm-debugging.txt, 1). | 29 | "platform" modes (see: Documents/power/basic-pm-debugging.txt, 1). |
30 | 30 | ||
31 | c) Compile the driver directly into the kernel and try the STD in the test mode. | 31 | c) Compile the driver directly into the kernel and try the test modes of |
32 | hibernation. | ||
32 | 33 | ||
33 | d) Attempt to suspend to disk with the driver compiled directly into the kernel | 34 | d) Attempt to hibernate with the driver compiled directly into the kernel |
34 | in the "reboot", "shutdown" and "platform" modes. | 35 | in the "reboot", "shutdown" and "platform" modes. |
35 | 36 | ||
36 | e) Attempt to suspend to RAM using the s2ram tool with the driver loaded (see: | 37 | e) Try the test modes of suspend (see: Documents/power/basic-pm-debugging.txt, |
37 | Documents/power/basic-pm-debugging.txt, 2). As far as the STR tests are | 38 | 2). [As far as the STR tests are concerned, it should not matter whether or |
38 | concerned, it should not matter whether or not the driver is built as a module. | 39 | not the driver is built as a module.] |
40 | |||
41 | f) Attempt to suspend to RAM using the s2ram tool with the driver loaded | ||
42 | (see: Documents/power/basic-pm-debugging.txt, 2). | ||
39 | 43 | ||
40 | Each of the above tests should be repeated several times and the STD tests | 44 | Each of the above tests should be repeated several times and the STD tests |
41 | should be mixed with the STR tests. If any of them fails, the driver cannot be | 45 | should be mixed with the STR tests. If any of them fails, the driver cannot be |
diff --git a/Documentation/power/notifiers.txt b/Documentation/power/notifiers.txt index 9293e4bc857c..ae1b7ec07684 100644 --- a/Documentation/power/notifiers.txt +++ b/Documentation/power/notifiers.txt | |||
@@ -28,6 +28,14 @@ PM_POST_HIBERNATION The system memory state has been restored from a | |||
28 | hibernation. Device drivers' .resume() callbacks have | 28 | hibernation. Device drivers' .resume() callbacks have |
29 | been executed and tasks have been thawed. | 29 | been executed and tasks have been thawed. |
30 | 30 | ||
31 | PM_RESTORE_PREPARE The system is going to restore a hibernation image. | ||
32 | If all goes well the restored kernel will issue a | ||
33 | PM_POST_HIBERNATION notification. | ||
34 | |||
35 | PM_POST_RESTORE An error occurred during the hibernation restore. | ||
36 | Device drivers' .resume() callbacks have been executed | ||
37 | and tasks have been thawed. | ||
38 | |||
31 | PM_SUSPEND_PREPARE The system is preparing for a suspend. | 39 | PM_SUSPEND_PREPARE The system is preparing for a suspend. |
32 | 40 | ||
33 | PM_POST_SUSPEND The system has just resumed or an error occured during | 41 | PM_POST_SUSPEND The system has just resumed or an error occured during |
diff --git a/Documentation/power/userland-swsusp.txt b/Documentation/power/userland-swsusp.txt index e00c6cf09e85..7b99636564c8 100644 --- a/Documentation/power/userland-swsusp.txt +++ b/Documentation/power/userland-swsusp.txt | |||
@@ -14,7 +14,7 @@ are going to develop your own suspend/resume utilities. | |||
14 | 14 | ||
15 | The interface consists of a character device providing the open(), | 15 | The interface consists of a character device providing the open(), |
16 | release(), read(), and write() operations as well as several ioctl() | 16 | release(), read(), and write() operations as well as several ioctl() |
17 | commands defined in kernel/power/power.h. The major and minor | 17 | commands defined in include/linux/suspend_ioctls.h . The major and minor |
18 | numbers of the device are, respectively, 10 and 231, and they can | 18 | numbers of the device are, respectively, 10 and 231, and they can |
19 | be read from /sys/class/misc/snapshot/dev. | 19 | be read from /sys/class/misc/snapshot/dev. |
20 | 20 | ||
@@ -27,17 +27,17 @@ once at a time. | |||
27 | The ioctl() commands recognized by the device are: | 27 | The ioctl() commands recognized by the device are: |
28 | 28 | ||
29 | SNAPSHOT_FREEZE - freeze user space processes (the current process is | 29 | SNAPSHOT_FREEZE - freeze user space processes (the current process is |
30 | not frozen); this is required for SNAPSHOT_ATOMIC_SNAPSHOT | 30 | not frozen); this is required for SNAPSHOT_CREATE_IMAGE |
31 | and SNAPSHOT_ATOMIC_RESTORE to succeed | 31 | and SNAPSHOT_ATOMIC_RESTORE to succeed |
32 | 32 | ||
33 | SNAPSHOT_UNFREEZE - thaw user space processes frozen by SNAPSHOT_FREEZE | 33 | SNAPSHOT_UNFREEZE - thaw user space processes frozen by SNAPSHOT_FREEZE |
34 | 34 | ||
35 | SNAPSHOT_ATOMIC_SNAPSHOT - create a snapshot of the system memory; the | 35 | SNAPSHOT_CREATE_IMAGE - create a snapshot of the system memory; the |
36 | last argument of ioctl() should be a pointer to an int variable, | 36 | last argument of ioctl() should be a pointer to an int variable, |
37 | the value of which will indicate whether the call returned after | 37 | the value of which will indicate whether the call returned after |
38 | creating the snapshot (1) or after restoring the system memory state | 38 | creating the snapshot (1) or after restoring the system memory state |
39 | from it (0) (after resume the system finds itself finishing the | 39 | from it (0) (after resume the system finds itself finishing the |
40 | SNAPSHOT_ATOMIC_SNAPSHOT ioctl() again); after the snapshot | 40 | SNAPSHOT_CREATE_IMAGE ioctl() again); after the snapshot |
41 | has been created the read() operation can be used to transfer | 41 | has been created the read() operation can be used to transfer |
42 | it out of the kernel | 42 | it out of the kernel |
43 | 43 | ||
@@ -49,39 +49,37 @@ SNAPSHOT_ATOMIC_RESTORE - restore the system memory state from the | |||
49 | 49 | ||
50 | SNAPSHOT_FREE - free memory allocated for the snapshot image | 50 | SNAPSHOT_FREE - free memory allocated for the snapshot image |
51 | 51 | ||
52 | SNAPSHOT_SET_IMAGE_SIZE - set the preferred maximum size of the image | 52 | SNAPSHOT_PREF_IMAGE_SIZE - set the preferred maximum size of the image |
53 | (the kernel will do its best to ensure the image size will not exceed | 53 | (the kernel will do its best to ensure the image size will not exceed |
54 | this number, but if it turns out to be impossible, the kernel will | 54 | this number, but if it turns out to be impossible, the kernel will |
55 | create the smallest image possible) | 55 | create the smallest image possible) |
56 | 56 | ||
57 | SNAPSHOT_AVAIL_SWAP - return the amount of available swap in bytes (the last | 57 | SNAPSHOT_GET_IMAGE_SIZE - return the actual size of the hibernation image |
58 | argument should be a pointer to an unsigned int variable that will | 58 | |
59 | SNAPSHOT_AVAIL_SWAP_SIZE - return the amount of available swap in bytes (the | ||
60 | last argument should be a pointer to an unsigned int variable that will | ||
59 | contain the result if the call is successful). | 61 | contain the result if the call is successful). |
60 | 62 | ||
61 | SNAPSHOT_GET_SWAP_PAGE - allocate a swap page from the resume partition | 63 | SNAPSHOT_ALLOC_SWAP_PAGE - allocate a swap page from the resume partition |
62 | (the last argument should be a pointer to a loff_t variable that | 64 | (the last argument should be a pointer to a loff_t variable that |
63 | will contain the swap page offset if the call is successful) | 65 | will contain the swap page offset if the call is successful) |
64 | 66 | ||
65 | SNAPSHOT_FREE_SWAP_PAGES - free all swap pages allocated with | 67 | SNAPSHOT_FREE_SWAP_PAGES - free all swap pages allocated by |
66 | SNAPSHOT_GET_SWAP_PAGE | 68 | SNAPSHOT_ALLOC_SWAP_PAGE |
67 | |||
68 | SNAPSHOT_SET_SWAP_FILE - set the resume partition (the last ioctl() argument | ||
69 | should specify the device's major and minor numbers in the old | ||
70 | two-byte format, as returned by the stat() function in the .st_rdev | ||
71 | member of the stat structure) | ||
72 | 69 | ||
73 | SNAPSHOT_SET_SWAP_AREA - set the resume partition and the offset (in <PAGE_SIZE> | 70 | SNAPSHOT_SET_SWAP_AREA - set the resume partition and the offset (in <PAGE_SIZE> |
74 | units) from the beginning of the partition at which the swap header is | 71 | units) from the beginning of the partition at which the swap header is |
75 | located (the last ioctl() argument should point to a struct | 72 | located (the last ioctl() argument should point to a struct |
76 | resume_swap_area, as defined in kernel/power/power.h, containing the | 73 | resume_swap_area, as defined in kernel/power/suspend_ioctls.h, |
77 | resume device specification, as for the SNAPSHOT_SET_SWAP_FILE ioctl(), | 74 | containing the resume device specification and the offset); for swap |
78 | and the offset); for swap partitions the offset is always 0, but it is | 75 | partitions the offset is always 0, but it is different from zero for |
79 | different to zero for swap files (please see | 76 | swap files (see Documentation/swsusp-and-swap-files.txt for details). |
80 | Documentation/swsusp-and-swap-files.txt for details). | 77 | |
81 | The SNAPSHOT_SET_SWAP_AREA ioctl() is considered as a replacement for | 78 | SNAPSHOT_PLATFORM_SUPPORT - enable/disable the hibernation platform support, |
82 | SNAPSHOT_SET_SWAP_FILE which is regarded as obsolete. It is | 79 | depending on the argument value (enable, if the argument is nonzero) |
83 | recommended to always use this call, because the code to set the resume | 80 | |
84 | partition may be removed from future kernels | 81 | SNAPSHOT_POWER_OFF - make the kernel transition the system to the hibernation |
82 | state (eg. ACPI S4) using the platform (eg. ACPI) driver | ||
85 | 83 | ||
86 | SNAPSHOT_S2RAM - suspend to RAM; using this call causes the kernel to | 84 | SNAPSHOT_S2RAM - suspend to RAM; using this call causes the kernel to |
87 | immediately enter the suspend-to-RAM state, so this call must always | 85 | immediately enter the suspend-to-RAM state, so this call must always |
@@ -93,24 +91,6 @@ SNAPSHOT_S2RAM - suspend to RAM; using this call causes the kernel to | |||
93 | to resume the system from RAM if there's enough battery power or restore | 91 | to resume the system from RAM if there's enough battery power or restore |
94 | its state on the basis of the saved suspend image otherwise) | 92 | its state on the basis of the saved suspend image otherwise) |
95 | 93 | ||
96 | SNAPSHOT_PMOPS - enable the usage of the hibernation_ops->prepare, | ||
97 | hibernate_ops->enter and hibernation_ops->finish methods (the in-kernel | ||
98 | swsusp knows these as the "platform method") which are needed on many | ||
99 | machines to (among others) speed up the resume by letting the BIOS skip | ||
100 | some steps or to let the system recognise the correct state of the | ||
101 | hardware after the resume (in particular on many machines this ensures | ||
102 | that unplugged AC adapters get correctly detected and that kacpid does | ||
103 | not run wild after the resume). The last ioctl() argument can take one | ||
104 | of the three values, defined in kernel/power/power.h: | ||
105 | PMOPS_PREPARE - make the kernel carry out the | ||
106 | hibernation_ops->prepare() operation | ||
107 | PMOPS_ENTER - make the kernel power off the system by calling | ||
108 | hibernation_ops->enter() | ||
109 | PMOPS_FINISH - make the kernel carry out the | ||
110 | hibernation_ops->finish() operation | ||
111 | Note that the actual constants are misnamed because they surface | ||
112 | internal kernel implementation details that have changed. | ||
113 | |||
114 | The device's read() operation can be used to transfer the snapshot image from | 94 | The device's read() operation can be used to transfer the snapshot image from |
115 | the kernel. It has the following limitations: | 95 | the kernel. It has the following limitations: |
116 | - you cannot read() more than one virtual memory page at a time | 96 | - you cannot read() more than one virtual memory page at a time |
@@ -122,7 +102,7 @@ The device's write() operation is used for uploading the system memory snapshot | |||
122 | into the kernel. It has the same limitations as the read() operation. | 102 | into the kernel. It has the same limitations as the read() operation. |
123 | 103 | ||
124 | The release() operation frees all memory allocated for the snapshot image | 104 | The release() operation frees all memory allocated for the snapshot image |
125 | and all swap pages allocated with SNAPSHOT_GET_SWAP_PAGE (if any). | 105 | and all swap pages allocated with SNAPSHOT_ALLOC_SWAP_PAGE (if any). |
126 | Thus it is not necessary to use either SNAPSHOT_FREE or | 106 | Thus it is not necessary to use either SNAPSHOT_FREE or |
127 | SNAPSHOT_FREE_SWAP_PAGES before closing the device (in fact it will also | 107 | SNAPSHOT_FREE_SWAP_PAGES before closing the device (in fact it will also |
128 | unfreeze user space processes frozen by SNAPSHOT_UNFREEZE if they are | 108 | unfreeze user space processes frozen by SNAPSHOT_UNFREEZE if they are |
@@ -133,16 +113,12 @@ snapshot image from/to the kernel will use a swap parition, called the resume | |||
133 | partition, or a swap file as storage space (if a swap file is used, the resume | 113 | partition, or a swap file as storage space (if a swap file is used, the resume |
134 | partition is the partition that holds this file). However, this is not really | 114 | partition is the partition that holds this file). However, this is not really |
135 | required, as they can use, for example, a special (blank) suspend partition or | 115 | required, as they can use, for example, a special (blank) suspend partition or |
136 | a file on a partition that is unmounted before SNAPSHOT_ATOMIC_SNAPSHOT and | 116 | a file on a partition that is unmounted before SNAPSHOT_CREATE_IMAGE and |
137 | mounted afterwards. | 117 | mounted afterwards. |
138 | 118 | ||
139 | These utilities SHOULD NOT make any assumptions regarding the ordering of | 119 | These utilities MUST NOT make any assumptions regarding the ordering of |
140 | data within the snapshot image, except for the image header that MAY be | 120 | data within the snapshot image. The contents of the image are entirely owned |
141 | assumed to start with an swsusp_info structure, as specified in | 121 | by the kernel and its structure may be changed in future kernel releases. |
142 | kernel/power/power.h. This structure MAY be used by the userland utilities | ||
143 | to obtain some information about the snapshot image, such as the size | ||
144 | of the snapshot image, including the metadata and the header itself, | ||
145 | contained in the .size member of swsusp_info. | ||
146 | 122 | ||
147 | The snapshot image MUST be written to the kernel unaltered (ie. all of the image | 123 | The snapshot image MUST be written to the kernel unaltered (ie. all of the image |
148 | data, metadata and header MUST be written in _exactly_ the same amount, form | 124 | data, metadata and header MUST be written in _exactly_ the same amount, form |
@@ -159,7 +135,7 @@ means, such as checksums, to ensure the integrity of the snapshot image. | |||
159 | The suspending and resuming utilities MUST lock themselves in memory, | 135 | The suspending and resuming utilities MUST lock themselves in memory, |
160 | preferrably using mlockall(), before calling SNAPSHOT_FREEZE. | 136 | preferrably using mlockall(), before calling SNAPSHOT_FREEZE. |
161 | 137 | ||
162 | The suspending utility MUST check the value stored by SNAPSHOT_ATOMIC_SNAPSHOT | 138 | The suspending utility MUST check the value stored by SNAPSHOT_CREATE_IMAGE |
163 | in the memory location pointed to by the last argument of ioctl() and proceed | 139 | in the memory location pointed to by the last argument of ioctl() and proceed |
164 | in accordance with it: | 140 | in accordance with it: |
165 | 1. If the value is 1 (ie. the system memory snapshot has just been | 141 | 1. If the value is 1 (ie. the system memory snapshot has just been |
@@ -173,7 +149,7 @@ in accordance with it: | |||
173 | image has been saved. | 149 | image has been saved. |
174 | (b) The suspending utility SHOULD NOT attempt to perform any | 150 | (b) The suspending utility SHOULD NOT attempt to perform any |
175 | file system operations (including reads) on the file systems | 151 | file system operations (including reads) on the file systems |
176 | that were mounted before SNAPSHOT_ATOMIC_SNAPSHOT has been | 152 | that were mounted before SNAPSHOT_CREATE_IMAGE has been |
177 | called. However, it MAY mount a file system that was not | 153 | called. However, it MAY mount a file system that was not |
178 | mounted at that time and perform some operations on it (eg. | 154 | mounted at that time and perform some operations on it (eg. |
179 | use it for saving the image). | 155 | use it for saving the image). |