We need hv_kbd_pm_notify() to make sure the pm_wakeup_hard_event() call
does not prevent the system from entering hibernation: the hibernation
is a relatively long process, which can be aborted by the call
pm_wakeup_hard_event(), which is invoked upon keyboard events.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
---

This patch is basically a pure Hyper-V specific change and it has a
build dependency on the commit 271b2224d42f ("Drivers: hv: vmbus: Implement
suspend/resume for VSC drivers for hibernation"), which is on Sasha Levin's
Hyper-V tree's hyperv-next branch:
https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/log/?h=hyperv-next

I request this patch should go through Sasha's tree rather than the
input subsystemi's tree.

Hi Dmitry, can you please Ack?

 drivers/input/serio/hyperv-keyboard.c | 68 ++++++++++++++++++++++++++++++++---
 1 file changed, 63 insertions(+), 5 deletions(-)

diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index 88ae7c2..277dc4c 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c

@@ -10,6 +10,7 @@
 #include <linux/hyperv.h>
 #include <linux/serio.h>
 #include <linux/slab.h>
+#include <linux/suspend.h>
 
 /*
  * Current version 1.0

@@ -95,6 +96,9 @@ struct hv_kbd_dev {
 	struct completion wait_event;
 	spinlock_t lock; /* protects 'started' field */
 	bool started;
+
+	struct notifier_block pm_nb;
+	bool hibernation_in_progress;