Re: How to wakup system from standby via USB keyboard

[Wu Zhangjin <wuzhangjin@gmail.com>]

On Fri, 2009-08-21 at 22:35 -0400, Alan Stern wrote:
> On Sat, 22 Aug 2009, Wu Zhangjin wrote:
> 
> > On Sat, 2009-08-22 at 00:06 +0200, Rafael J. Wysocki wrote:
> > > On Friday 21 August 2009, Wu Zhangjin wrote:
> > > > Hi All,
> > > > 
> > > > After reading some documents in Documentation/ and the Internet, I found
> > > > there is an interface /proc/acpi/wakeup to set the wakeup devices on
> > > > machines support ACPI. but my machine does not support ACPI,
> > > > no /proc/acpi/wakeup there.
> > > > 
> > > > my machine is FuLoong2F, which is loongson based machine, it does not
> > > > support ACPI, but currently, I have made it support basic standby mode
> > > > for it has a 'wait' mode(after setting it's frequency to ZERO) and can
> > > > be waked up via an external interrupt. and here is the basic framework:
> > > > 
> > > > 0. suspend:
> > > > 
> > > > arch_suspend_disable_irqs(disable all interrupts)
> > > > 
> > > > ...
> > > > 
> > > > fuloong_pm_enter()
> > > > 
> > > > ...
> > > > 
> > > > arch_suspend_enable_irqs(enable all interrupts)
> > > > 
> > > > 1. fuloong_pm_enter:
> > > > 
> > > > setup_wakeup_interrupts()
> > > > 
> > > > loongson_pm_enter(put loongson into 'wait' mode)
> > > > 
> > > > 3. setup_wakeup_interrupts
> > > > 
> > > > if the interrupt line is connected to loongson directly, no setup need
> > > > to do, but if there is an interrupt line connected to loongson
> > > > indirectly(i.e via i8259A), I need to get through the interrupt path via
> > > > enable(un-mask) the interrupts in interrupt controller and resuming the
> > > > devices earlier manually or enable the interrupt bit on the devices and
> > > > even or set a flag of the device driver to tell the system not suspend
> > > > this device.
> > > > 
> > > > I have tried the first(resuming earlier) and second method(enable the
> > > > interrupt bit) on the 8042 keyboard o YeeLoong(another loongson-based
> > > > machine, a netbook, i8042 is connected to i8259A directly), it works
> > > > well, but not tried the third method yet.
> > > > 
> > > > I guess the /proc/acpi/wakeup based method in user-space should be
> > > > something like this, but is there any relative method in kernel space?
> > > > 
> > > > there are only USB interfaces on FuLoong2F machines, I guess it will be
> > > > very hard to get through the interrupt path via the above two methods(I
> > > > have tried to enable the USB interrupt in south bridge, but not work),
> > > > so, is there an easier method to do it?
> > > 
> > > Is your USB controller a PCI one?
> > 
> > Yes.
> > 
> > and I just checked the file: drivers/usb/host/ohci-pci.c, there are two
> > functions ohci_pci_suspend/ohci_pci_resume there, perhaps I can call
> > these two functions directly to resume it earlier and suspend it again
> > before the real resuming, any easier methods? is there a flag to tell
> > the system not suspend it or just not disable the interrupt request?
> 
> I think the interface you're looking for is
> 
> 	/sys/bus/usb/devices/usbN/../power/wakeup
> 
> where N is the USB bus number.  This file defaults to "disabled"; if
> you write "enabled" to it then the USB host controller will be enabled
> as a wakeup source.  This should work even without ACPI; it uses the
> PCI PME mechanism.
> 

I checked the /sys/bus/usb.../wakeup interfaces, seems the
usbN/power/wakeup interfaces are enabled by default in my machine, but
the usbN/N-X:Y/power/wakeup is not available. so, I can not wakeup the
system via any USB devices.

Here is the output:

$ find /sys/bus/usb/devices/usb1/ -name "wakeup" -exec echo {} \; -exec
cat '{}' \;
/sys/bus/usb/devices/usb1/power/wakeup
enabled
/sys/bus/usb/devices/usb1/1-0:1.0/power/wakeup

/sys/bus/usb/devices/usb1/1-3/power/wakeup
enabled
/sys/bus/usb/devices/usb1/1-3/1-3:1.0/power/wakeup

/sys/bus/usb/devices/usb1/1-3/1-3:1.1/power/wakeup

/sys/bus/usb/devices/usb1/1-4/power/wakeup
enabled
/sys/bus/usb/devices/usb1/1-4/1-4:1.0/power/wakeup

$ find /sys/bus/usb/devices/usb2/ -name "wakeup" -exec echo {} \; -exec
cat '{}' \;
/sys/bus/usb/devices/usb2/power/wakeup
enabled
/sys/bus/usb/devices/usb2/2-0:1.0/power/wakeup

Thanks,
Wu Zhangjin