This change is specific to Hyper-V based VMs. 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.

$echo freeze > /sys/power/state

bash: echo: write error: Operation not supported

Fixes: 1a06d017fb3f ("Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM") Cc: stable@vger.kernel.org Signed-off-by: Saurabh Sengar ssengar@linux.microsoft.com Signed-off-by: Erni Sri Satya Vennela ernis@linux.microsoft.com --- Changes in v2: * Add "#define vmbus_freeze NULL" when CONFIG_PM_SLEEP is not enabled. * Change commit message to clarify that this change is specifc to Hyper-V based VMs. Changes in v3: * Add 'Cc: stable@vger.kernel.org' in sign-off area. --- drivers/hv/vmbus_drv.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 965d2a4efb7e..8f445c849512 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -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,