Use PM_FREEZE, PM_THAW and PM_RESTORE power events for
suspend/resume/checkpoint functionality, instead of PM_SUSPEND
and PM_RESUME. Use of these pm events fixes the Xen Guest hangup
when taking checkpoints. When a suspend event is cancelled
(while taking checkpoints once/continuously), we use PM_THAW
instead of PM_RESUME. PM_RESTORE is used when suspend is not
cancelled. See Documentation/power/devices.txt and linux/pm.h
for more info about freeze, thaw and restore. The sequence of
pm events in a suspend-resume scenario is shown below.
dpm_suspend_start(PMSG_FREEZE);
dpm_suspend_noirq(PMSG_FREEZE);
sysdev_suspend(PMSG_FREEZE);
cancelled = suspend_hypercall()
sysdev_resume();
dpm_resume_noirq(cancelled ? PMSG_THAW : PMSG_RESTORE);
dpm_resume_end(cancelled ? PMSG_THAW : PMSG_RESTORE);
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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