Patch 2e711c04dbbf7a7732a3f7073b1fc285d12b369d
(PM: Remove sysdev suspend, resume and shutdown operations)
deleted sysdev_suspend(), which was being relied on to call
check_wakeup_irqs() in suspend.  If check_wakeup_irqs() is not
called, wake interrupts that are pending when suspend is
entered may be lost.  It also breaks IRQCHIP_MASK_ON_SUSPEND,
which is handled in check_wakeup_irqs().

This patch adds a call to check_wakeup_irqs() in syscore_suspend(),
similar to what was deleted in sysdev_suspend().

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Device suspend/resume infrastructure is used not only by the suspend
and hibernate code in kernel/power, but also by APM, Xen and the
kexec jump feature.  However, commit 40dc166cb5dddbd36aa4ad11c03915ea
(PM / Core: Introduce struct syscore_ops for core subsystems PM)
failed to add syscore_suspend() and syscore_resume() calls to that
code, which generally leads to breakage when the features in question
are used.

To fix this problem, add the missing syscore_suspend() and
syscore_resume() calls to arch/x86/kernel/apm_32.c, kernel/kexec.c
and drivers/xen/manage.c.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

Some subsystems need to carry out suspend/resume and shutdown
operations with one CPU on-line and interrupts disabled.  The only
way to register such operations is to define a sysdev class and
a sysdev specifically for this purpose which is cumbersome and
inefficient.  Moreover, the arguments taken by sysdev suspend,
resume and shutdown callbacks are practically never necessary.

For this reason, introduce a simpler interface allowing subsystems
to register operations to be executed very late during system suspend
and shutdown and very early during resume in the form of
strcut syscore_ops objects.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>