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    SubjectRe: [PATCH] genirq: do not disable IRQ_WAKEUP marked irqs on suspend
    On Fri, 12 Jun 2009 21:52:46 +0200 (CEST)
    Thomas Gleixner <tglx@linutronix.de> wrote:

    > On Fri, 12 Jun 2009, Kevin Hilman wrote:
    > > http://lkml.org/lkml/2009/5/4/448
    > >
    > > Only difference is I did the checking outside of the lock, which is
    > > probably wrong. In any case, you'll be interested in the thread that
    > > follows.
    >
    > Hmm, darn. That means that on hardware which has trouble with the
    > delayed disable and therefor uses it's own chip->disable_irq() method
    > the suspend logic is wreckaged.

    Does this maen that your original patch is no longer applicable to
    mainline/-stable?


    > But there is always a way to get broken hardware tamed. :)
    >
    > suspend does:
    > __disable_irq();
    > status |= IRQ_SUSPENDED;
    > chip->disable_irq();
    >
    > resume does:
    > __enable_irq();
    > status &= ~IRQ_SUSPENDED;
    > chip->enable_irq();
    >
    > So
    >
    > - set_irq_handler(handle_level_irq);
    > + set_irq_handler(my_own_handler);
    >
    > +my_own_handler()
    > +{
    > + if (!(status & IRQ_SUSPENDED)) {
    > + handle_level_irq();
    > + } else {
    > + mask_at_hardware_level();
    > + status |= IRQ_PENDING;
    > + save_important_information();
    > + }
    > +}
    >
    > my_disable_irq()
    > {
    > + if (!(status & IRQ_SUSPENDED))
    > mask_at_hardware_level();
    > }
    >
    > my_enable_irq()
    > {
    > + if (important_information_has_been_saved)
    > + replay_what_happened();
    > +
    > unmask_at_hardware_level();
    > }
    >
    > Ugly, but that might work somehow. Not sure about the replay part, but
    > that can be deferred via some more hackery as well :)
    >
    > Raphael, these delayed disable and the chip->irq_disable() override
    > implications vs. suspend really need to be documented. The current
    > comment of suspend_device_irqs() is bogus:
    >
    > * During system-wide suspend or hibernation device interrupts need to be
    > * disabled at the chip level and this function is provided for this purpose.
    > ^^^^^^^^^^^^^^^^^^^^^^^^^^



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