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Drivers: hv: vmbus: Disable Suspend-to-Idle for VMBus

PATCH Superseded Erni Sri Satya Vennela 1 participant 1 message Dec 16, 2024 1 message not in the archive

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Erni Sri Satya Vennela

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PATCH v4 1/3 Drivers: hv: vmbus: Disable Suspend-to-Idle for VMBus

This change is specific to Hyper-V VM user.
If the Virtual Machine Connection window is focused, a Hyper-V VM user can unintentionally touch the keyboard/mouse when the VM is hibernating or resuming, and consequently the hibernation or resume operation can be aborted unexpectedly. Fix the issue by no longer registering the keyboard/mouse as wakeup devices (see the other two patches for the changes to drivers/input/serio/hyperv-keyboard.c and drivers/hid/hid-hyperv.c).

The keyboard/mouse were registered as wakeup devices because the VM needs to be woken up from the Suspend-to-Idle state after a user runs "echo freeze > /sys/power/state". It seems like the Suspend-to-Idle feature has no real users in practice, so let's no longer support that by returning -EOPNOTSUPP if a user tries to use that.

Fixes 1a06d017fb3f ("Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM")
Cc [email protected]
Signed-off-by Saurabh Sengar <[email protected]>
Signed-off-by Erni Sri Satya Vennela <[email protected]>>

---
Changes in v4:
* No change

Changes in v3:
* Add "Cc: [email protected]" in sign-off area.

Changes in v2:
* Add "#define vmbus_freeze NULL" when CONFIG_PM_SLEEP is not enabled.

---
 drivers/hv/vmbus_drv.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)
drivers/hv/vmbus_drv.c +15 -1
index 6d89d37b069a..4df6b12bf6a1 100644
@@ -900,6 +900,19 @@ static void vmbus_shutdown(struct device *child_device)
 }
 
 #ifdef CONFIG_PM_SLEEP
+/*
+ * vmbus_freeze - Suspend-to-Idle
+ */
+static int vmbus_freeze(struct device *child_device)
+{
+/*
+ * Do not support Suspend-to-Idle ("echo freeze > /sys/power/state") as
+ * that would require registering the Hyper-V synthetic mouse/keyboard
+ * devices as wakeup devices, which can abort hibernation/resume unexpectedly.
+ */
+	return -EOPNOTSUPP;
+}
+
 /*
  * vmbus_suspend - Suspend a vmbus device
  */

@@ -938,6 +951,7 @@ static int vmbus_resume(struct device *child_device)
 	return drv->resume(dev);
 }
 #else
+#define vmbus_freeze NULL
 #define vmbus_suspend NULL
 #define vmbus_resume NULL
 #endif /* CONFIG_PM_SLEEP */

@@ -969,7 +983,7 @@ static void vmbus_device_release(struct device *device)
  */
 
 static const struct dev_pm_ops vmbus_pm = {
-	.suspend_noirq	= NULL,
+	.suspend_noirq  = vmbus_freeze,
 	.resume_noirq	= NULL,
 	.freeze_noirq	= vmbus_suspend,
 	.thaw_noirq	= vmbus_resume,
Signature · 1 line
2.34.1