RE: [PATCH v2] Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM

[Michael Kelley]

From: Dexuan Cui <decui@xxxxxxxxxxxxx> Sent: Friday, April 10, 2020 10:08 PM
> 
> Before the hibernation patchset (e.g. f53335e3289f), in a Generation-2
> Linux VM on Hyper-V, the user can run "echo freeze > /sys/power/state" to
> freeze the system, i.e. Suspend-to-Idle. The user can press the keyboard
> or move the mouse to wake up the VM.
> 
> With the hibernation patchset, Linux VM on Hyper-V can hibernate to disk,
> but Suspend-to-Idle is broken: when the synthetic keyboard/mouse are
> suspended, there is no way to wake up the VM.
> 
> Fix the issue by not suspending and resuming the vmbus devices upon
> Suspend-to-Idle.
> 
> Fixes: f53335e3289f ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for
> hibernation")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
> ---
> 
> Changes in v2:
>     Added "#define vmbus_suspend NULL", etc. for the case where
> CONFIG_PM_SLEEP is not defined.
>     Many thanks to kbuild test robot <lkp@xxxxxxxxx> for this!
> 
>  drivers/hv/vmbus_drv.c | 43 ++++++++++++++++++++++++++++++++++---------
>  1 file changed, 34 insertions(+), 9 deletions(-)
> 

Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>