EHCI powersave causes shutdown to freeze

EHCI powersave causes shutdown to freeze

[Patrik Kullman]

Hi,

After creating a powersave script based on PowerTOP Tunables, this
particular line prevented the system from being able to shutdown (Asus
Zenbook UX31E, kernels 3.0 - 3.1.2):

### Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced
Host Controller #1
echo auto > /sys/bus/pci/devices/0000:00:1d.0/power/control


Kernel prints the "Power Down." message but machine doesn't power down.

Is this a known bug?
Could this be fixed in the driver instead of:

echo on > /sys/bus/pci/devices/0000:00:1d.0/power/control

on system shutdown?

Re: EHCI powersave causes shutdown to freeze

[Rafael J. Wysocki]

On Thursday, November 24, 2011, Patrik Kullman wrote:
> Hi,
> 
> After creating a powersave script based on PowerTOP Tunables, this
> particular line prevented the system from being able to shutdown (Asus
> Zenbook UX31E, kernels 3.0 - 3.1.2):
> 
> ### Intel Corporation 6 Series/C200 Series Chipset Family USB Enhanced
> Host Controller #1
> echo auto > /sys/bus/pci/devices/0000:00:1d.0/power/control
> 
> 
> Kernel prints the "Power Down." message but machine doesn't power down.
> 
> Is this a known bug?
> Could this be fixed in the driver instead of:
> 
> echo on > /sys/bus/pci/devices/0000:00:1d.0/power/control
> 
> on system shutdown?

This commit should address that issue:

commit af8db1508f2c9f3b6e633e2d2d906c6557c617f9
Author: Peter Chen <peter.chen@freescale.com>
Date:   Tue Nov 15 21:52:29 2011 +0100

    PM / driver core: disable device's runtime PM during shutdown

Thanks,
Rafael