On Sun, Mar 1, 2009 at 2:24 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote:
> From: Rafael J. Wysocki <rjw@xxxxxxx>
>
> Introduce two helper functions allowing us to prevent device drivers
> from getting any interrupts (without disabling interrupts on the CPU)
> during suspend (or hibernation) and to make them start to receive
> interrupts again during the subsequent resume, respectively. These
> functions make it possible to keep timer interrupts enabled while the
> "late" suspend and "early" resume callbacks provided by device
> drivers are being executed.
>
> Use these functions to rework the handling of interrupts during
> suspend (hibernation) and resume. Namely, interrupts will only be
> disabled on the CPU right before suspending sysdevs, while device
> drivers will be prevented from receiving interrupts, with the help of
> the new helper function, before their "late" suspend callbacks run
> (and analogously during resume).
>
> In addition, since the device interrups are now disabled before the
> CPU has turned all interrupts off and the CPU will ACK the interrupts
> setting the IRQ_PENDING bit for them, check in sysdev_suspend() if
> any wake-up interrupts are pending and abort suspend if that's the
> case.
>
> +void resume_device_irqs(void)
> +{
> + struct irq_desc *desc;
> + int irq;
> +
> + for_each_irq_desc(irq, desc)
> + if (desc->status & IRQ_SUSPENDED)
> + enable_irq(irq);
> +}
I think you need to clear IRQ_SUSPENDED here, not in enable_irq.
> @@ -222,8 +222,9 @@ static void __enable_irq(struct irq_desc
> WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq);
> break;
> case 1: {
> - unsigned int status = desc->status & ~IRQ_DISABLED;
> + unsigned int status;
>
> + status = desc->status & ~(IRQ_DISABLED | IRQ_SUSPENDED);
> /* Prevent probing on this irq: */
> desc->status = status | IRQ_NOPROBE;
> check_irq_resend(desc, irq);
This only clears IRQ_SUSPENDED if the interrupt was not disabled
elsewhere. If a driver calls interrupt_disable in suspend_late, but
calls interrupt_enable lazily, resume_device_irqs will reenable the
interrupt even though the driver has a disable reference.
The rest of the patch looks good.
--
Arve Hjønnevåg
_______________________________________________
linux-pm mailing list
linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linux-foundation.org/mailman/listinfo/linux-pm
