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| author | Rafael J. Wysocki <rjw@sisk.pl> | 2007-10-26 01:01:10 +0200 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-02-01 18:30:53 -0500 |
| commit | eb57c1cf059630454b40fb8bb124e3f318d241f8 (patch) | |
| tree | df8abba4265647f15b3b30053a4d843099bb6b9e /Documentation | |
| parent | af508b34d27e3341287d89e0eae6752fdb1b873f (diff) | |
| download | lwn-eb57c1cf059630454b40fb8bb124e3f318d241f8.tar.gz lwn-eb57c1cf059630454b40fb8bb124e3f318d241f8.zip | |
Hibernation: Rework platform support ioctls (rev. 2)
Modify the hibernation userland interface by adding two new ioctls to it,
SNAPSHOT_PLATFORM_SUPPORT and SNAPSHOT_POWER_OFF, that can be used,
respectively, to switch the hibernation platform support on/off and to make the
kernel transition the system to the hibernation state (eg. ACPI S4) using the
platform (eg. ACPI) driver.
These ioctls are intended to replace the misdesigned SNAPSHOT_PMOPS ioctl,
which from now is regarded as obsolete and will be removed in the future.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/power/userland-swsusp.txt | 24 |
1 files changed, 6 insertions, 18 deletions
diff --git a/Documentation/power/userland-swsusp.txt b/Documentation/power/userland-swsusp.txt index 32f187479697..381e9c0fb9d6 100644 --- a/Documentation/power/userland-swsusp.txt +++ b/Documentation/power/userland-swsusp.txt @@ -85,6 +85,12 @@ SNAPSHOT_SET_SWAP_AREA - set the resume partition and the offset (in <PAGE_SIZE> recommended to always use this call, because the code to set the resume partition may be removed from future kernels +SNAPSHOT_PLATFORM_SUPPORT - enable/disable the hibernation platform support, + depending on the argument value (enable, if the argument is nonzero) + +SNAPSHOT_POWER_OFF - make the kernel transition the system to the hibernation + state (eg. ACPI S4) using the platform (eg. ACPI) driver + SNAPSHOT_S2RAM - suspend to RAM; using this call causes the kernel to immediately enter the suspend-to-RAM state, so this call must always be preceded by the SNAPSHOT_FREEZE call and it is also necessary @@ -95,24 +101,6 @@ SNAPSHOT_S2RAM - suspend to RAM; using this call causes the kernel to to resume the system from RAM if there's enough battery power or restore its state on the basis of the saved suspend image otherwise) -SNAPSHOT_PMOPS - enable the usage of the hibernation_ops->prepare, - hibernate_ops->enter and hibernation_ops->finish methods (the in-kernel - swsusp knows these as the "platform method") which are needed on many - machines to (among others) speed up the resume by letting the BIOS skip - some steps or to let the system recognise the correct state of the - hardware after the resume (in particular on many machines this ensures - that unplugged AC adapters get correctly detected and that kacpid does - not run wild after the resume). The last ioctl() argument can take one - of the three values, defined in kernel/power/power.h: - PMOPS_PREPARE - make the kernel carry out the - hibernation_ops->prepare() operation - PMOPS_ENTER - make the kernel power off the system by calling - hibernation_ops->enter() - PMOPS_FINISH - make the kernel carry out the - hibernation_ops->finish() operation - Note that the actual constants are misnamed because they surface - internal kernel implementation details that have changed. - The device's read() operation can be used to transfer the snapshot image from the kernel. It has the following limitations: - you cannot read() more than one virtual memory page at a time |