[PATCH] HID: hyperv: Add the support of hibernation

From: Dexuan Cui
Date: Wed Sep 11 2019 - 19:36:11 EST


We need mousevsc_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 mouse events.

Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
---

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 subsystem's tree.

Hi Jiri, Benjamin, can you please Ack?

drivers/hid/hid-hyperv.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 69 insertions(+), 2 deletions(-)

diff --git a/drivers/hid/hid-hyperv.c b/drivers/hid/hid-hyperv.c
index cc5b09b8..e798740 100644
--- a/drivers/hid/hid-hyperv.c
+++ b/drivers/hid/hid-hyperv.c
@@ -12,6 +12,7 @@
#include <linux/hid.h>
#include <linux/hiddev.h>
#include <linux/hyperv.h>
+#include <linux/suspend.h>


struct hv_input_dev_info {
@@ -150,6 +151,9 @@ struct mousevsc_dev {
struct hv_input_dev_info hid_dev_info;
struct hid_device *hid_device;
u8 input_buf[HID_MAX_BUFFER_SIZE];
+
+ struct notifier_block pm_nb;
+ bool hibernation_in_progress;
};


@@ -192,6 +196,9 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
if (desc->bLength == 0)
goto cleanup;

+ /* The pointer is not NULL when we resume from hibernation */
+ if (input_device->hid_desc != NULL)
+ kfree(input_device->hid_desc);
input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);

if (!input_device->hid_desc)
@@ -203,6 +210,9 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
goto cleanup;
}

+ /* The pointer is not NULL when we resume from hibernation */
+ if (input_device->report_desc != NULL)
+ kfree(input_device->report_desc);
input_device->report_desc = kzalloc(input_device->report_desc_size,
GFP_ATOMIC);

@@ -243,7 +253,7 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
}

static void mousevsc_on_receive(struct hv_device *device,
- struct vmpacket_descriptor *packet)
+ const struct vmpacket_descriptor *packet)
{
struct pipe_prt_msg *pipe_msg;
struct synthhid_msg *hid_msg;
@@ -301,7 +311,8 @@ static void mousevsc_on_receive(struct hv_device *device,
hid_input_report(input_dev->hid_device, HID_INPUT_REPORT,
input_dev->input_buf, len, 1);

- pm_wakeup_hard_event(&input_dev->device->device);
+ if (!input_dev->hibernation_in_progress)
+ pm_wakeup_hard_event(&input_dev->device->device);

break;
default:
@@ -378,6 +389,8 @@ static int mousevsc_connect_to_vsp(struct hv_device *device)
struct mousevsc_prt_msg *request;
struct mousevsc_prt_msg *response;

+ reinit_completion(&input_dev->wait_event);
+
request = &input_dev->protocol_req;
memset(request, 0, sizeof(struct mousevsc_prt_msg));

@@ -475,6 +488,29 @@ static int mousevsc_hid_raw_request(struct hid_device *hid,

static struct hid_driver mousevsc_hid_driver;

+static int mousevsc_pm_notify(struct notifier_block *nb,
+ unsigned long val, void *ign)
+{
+ struct mousevsc_dev *input_dev;
+
+ input_dev = container_of(nb, struct mousevsc_dev, pm_nb);
+
+ switch (val) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_RESTORE_PREPARE:
+ input_dev->hibernation_in_progress = true;
+ return NOTIFY_OK;
+
+ case PM_POST_HIBERNATION:
+ case PM_POST_RESTORE:
+ input_dev->hibernation_in_progress = false;
+ return NOTIFY_OK;
+
+ default:
+ return NOTIFY_DONE;
+ }
+}
+
static int mousevsc_probe(struct hv_device *device,
const struct hv_vmbus_device_id *dev_id)
{
@@ -549,6 +585,9 @@ static int mousevsc_probe(struct hv_device *device,
input_dev->connected = true;
input_dev->init_complete = true;

+ input_dev->pm_nb.notifier_call = mousevsc_pm_notify;
+ register_pm_notifier(&input_dev->pm_nb);
+
return ret;

probe_err2:
@@ -568,6 +607,8 @@ static int mousevsc_remove(struct hv_device *dev)
{
struct mousevsc_dev *input_dev = hv_get_drvdata(dev);

+ unregister_pm_notifier(&input_dev->pm_nb);
+
device_init_wakeup(&dev->device, false);
vmbus_close(dev->channel);
hid_hw_stop(input_dev->hid_device);
@@ -577,6 +618,30 @@ static int mousevsc_remove(struct hv_device *dev)
return 0;
}

+static int mousevsc_suspend(struct hv_device *dev)
+{
+ vmbus_close(dev->channel);
+
+ return 0;
+}
+
+static int mousevsc_resume(struct hv_device *dev)
+{
+ int ret;
+
+ ret = vmbus_open(dev->channel,
+ INPUTVSC_SEND_RING_BUFFER_SIZE,
+ INPUTVSC_RECV_RING_BUFFER_SIZE,
+ NULL, 0,
+ mousevsc_on_channel_callback,
+ dev);
+ if (ret)
+ return ret;
+
+ ret = mousevsc_connect_to_vsp(dev);
+ return ret;
+}
+
static const struct hv_vmbus_device_id id_table[] = {
/* Mouse guid */
{ HV_MOUSE_GUID, },
@@ -590,6 +655,8 @@ static int mousevsc_remove(struct hv_device *dev)
.id_table = id_table,
.probe = mousevsc_probe,
.remove = mousevsc_remove,
+ .suspend = mousevsc_suspend,
+ .resume = mousevsc_resume,
.driver = {
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
--
1.8.3.1