Hibernation: Enter platform hibernation state in a consistent way
authorRafael J. Wysocki <rjw@sisk.pl>
Thu, 18 Oct 2007 10:04:56 +0000 (03:04 -0700)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Thu, 18 Oct 2007 21:37:20 +0000 (14:37 -0700)
commit9cd9a0058dd35268b24fa16795a92c800f4086d4
tree2525a95542eaa16a9aea865e8078cf66f3274e18
parentc7e0831d385d620a58d95b25e4afa9b643f9a411
Hibernation: Enter platform hibernation state in a consistent way

Make hibernation_platform_enter() execute the enter-a-sleep-state sequence
instead of the mixed shutdown-with-entering-S4 thing.

Replace the shutting down of devices done by kernel_shutdown_prepare(), before
entering the ACPI S4 sleep state, with suspending them and the shutting down
of sysdevs with calling device_power_down(PMSG_SUSPEND) (just like before
entering S1 or S3, but the target state is now S4).   Also, disable the
nonboot CPUs before entering the sleep state (S4), which generally always is a
good idea.

This is known to fix the "double disk spin down during hibernation" on some
machines, eg.  HPC nx6325 (ref.  http://lkml.org/lkml/2007/8/7/316 and the
following thread).   Moreover, it has been reported to make
/sys/class/rtc/rtc0/wakealarm work correctly with hibernation for some users.
It also generally causes the hibernation state (ACPI S4) to be entered faster.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kernel/power/disk.c