Re: How to wakup system from standby via USB keyboard

[Wu Zhangjin <wuzhangjin@gmail.com>]

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?

Thanks,
Wu Zhangjin