On Fri, 2007-11-09 at 12:45 +0300, Alexey Starikovskiy wrote:
> Shaohua,
> There is cond_resched() before the exit from deferred execution routine,
> specifically to let notify thread a chance to execute.
> Thus by the time deferred execution is exited, notify should be already
> done,
> and we could safely enable _Lxx again.
> Do you think it is not sufficient?
Certainly not. A resched() can help to give a chance for other threads
to execute, but it's very unreliable. If it works, just because of luck.
We should add a wait there to guarantee.
Thanks,
Shaohua
>
> Li, Shaohua wrote:
> > Bob & Ming,
> > I'm working on adding wakeup GPE support at system runtime, this
> > capability can help us
> > Identify which device invokes a wakeup event at runtime, this is
> > required for runtime device
> > Power management.
> >
> > Below is the ASL code. For example, _L0c, USB3 will send a wakeup GPE
> > and invoke
> > a notify. In the notify handler, OS will clear USB3's PCI PME status to
> > avoid wakeup
> > event flood. But in current code, acpi_ev_asynch_execute_gpe_method will
> > start an asynchronous
> > execution of notify and return soon. Just before the return,
> > acpi_ev_asynch_execute_gpe_method
> > will reenable GPE 0C. That means GPE is enabled before OS execute
> > notification handler and USB3's
> > PCI PME status is cleared, and cause GPE flood. Ideally, I think we
> > should delay GPE enable
> > of _L0c till notification handler is finished or simply the method _L0c
> > is really finished.
> > What do you think?
> >
> > Thanks,
> > Shaohua
> >
> >
> > Method (_L0C, 0, NotSerialized)
> > {
> > Notify (\_SB.PCI0.USB3, 0x02)
> > }
> >
> > Method (_L0D, 0, NotSerialized)
> > {
> > Notify (\_SB.PCI0.USB7, 0x02)
> > }
> >
> > Method (_L0E, 0, NotSerialized)
> > {
> > Notify (\_SB.PCI0.USB4, 0x02)
> > }
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