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

From: [email-masked] (Marc Zyngier)
Date: Fri, 06 Feb 2015 09:02:09 +0000

On 05/02/15 23:33, Bjorn Andersson wrote:
> On Wed, Jan 7, 2015 at 9:51 AM, Marc Zyngier <[email-masked]> 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 <[email-masked]>
>> Tested-by: Bjorn Andersson <[email-masked]>
>> Signed-off-by: Marc Zyngier <[email-masked]>
> 
> 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.

None so far.

Thomas, do you have any comment on this one?

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...