Re: [PATCH v3 1/3] genirq: Allow the irqchip state of an IRQ to be save/restored

From: Bjorn Andersson
Date: Thu Feb 05 2015 - 18:33:29 EST


On Wed, Jan 7, 2015 at 9:51 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote:
> There is a number of cases where a kernel subsystem may want to
> introspect the state of an interrupt at the irqchip level:
>
> - When a peripheral is shared between virtual machines,
> its interrupt state becomes part of the guest's state,
> and must be switched accordingly. KVM on arm/arm64 requires
> this for its guest-visible timer
> - Some GPIO controllers seem to require peeking into the
> interrupt controller they are connected to to report
> their internal state
>
> This seem to be a pattern that is common enough for the core code
> to try and support this without too many horrible hacks. Introduce
> a pair of accessors (irq_get_irqchip_state/irq_set_irqchip_state)
> to retrieve the bits that can be of interest to another subsystem:
> pending, active, and masked.
>
> - irq_get_irqchip_state returns the state of the interrupt according
> to a parameter set to IRQCHIP_STATE_PENDING, IRQCHIP_STATE_ACTIVE,
> IRQCHIP_STATE_MASKED or IRQCHIP_STATE_LINE_LEVEL.
> - irq_set_irqchip_state similarly sets the state of the interrupt.
>
> Reviewed-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
> Tested-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>

Any update on the status of this?

I would like to be able to move ahead with the pinctrl driver for the
Qualcomm PM8921 pmic, that depends on this being in place.

Regards,
Bjorn
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