Re: [PATCH] genirq: do not disable IRQ_WAKEUP marked irqs on suspend

From: Kevin Hilman
Date: Fri Jun 12 2009 - 14:34:03 EST


Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes:

> On Fri, 12 Jun 2009, Kevin Hilman wrote:
>> Thomas Gleixner <tglx@xxxxxxxxxxxxx> writes:
>>
>> > commit 0a0c5168df (PM: Introduce functions for suspending and resuming
>> > device interrupts) iterates through all interrupts and disables them
>> > on the hardware level. Some architectures have functionality
>> > implemented to mark an interrupt source as wakeup source for suspend,
>> > but the new power management code disables them unconditionally which
>> > breaks the resume on interrupt functionality.
>> >
>> > The wakeup interrupts are marked in the status with the IRQ_WAKEUP
>> > bit. Skip the disablement for those interrupts which have the
>> > IRQ_WAKEUP bit set.
>> >
>> > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
>> > Cc: stable@xxxxxxxxxx
>>
>> Hi Thomas,
>>
>> I posted the same patch last month and lost the argument, original
>> thread here:
>>
>> http://lkml.org/lkml/2009/5/6/549
>
> Err no. Care to look at the difference ?

Oops, sent link to wrong patch. Here's the one solving the same problem:

http://marc.info/?l=linux-kernel&m=124148347804447&w=2

or

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.

Kevin

> I missed the above discussion, but I'm revisiting the delayed disable
> issue.
>
>>
>> > diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
>> > index 638d8be..bce6afd 100644
>> > --- a/kernel/irq/pm.c
>> > +++ b/kernel/irq/pm.c
>> > @@ -29,7 +29,8 @@ void suspend_device_irqs(void)
>> > unsigned long flags;
>> >
>> > spin_lock_irqsave(&desc->lock, flags);
>> > - __disable_irq(desc, irq, true);
>> > + if (!(desc->status & IRQ_WAKEUP))
>> > + __disable_irq(desc, irq, true);
>> > spin_unlock_irqrestore(&desc->lock, flags);
>> > }
>> >
>> > --
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