Re: [virtio-dev] Re: [PATCH V6 2/2] virtio-gpio: Add support for interrupts

[Viresh Kumar <viresh.kumar@linaro.org>]

On 27-07-21, 13:16, Arnd Bergmann wrote:
> This was under the assumption that we decide to still keep some
> controlq request that sets the irq type and just remove the 'mask'
> command.

Right, so I think I can fold all three of irq messages, mask, unmask
and type, to a single message type. Where the value of type can play
the role of masking/unmasking. This should work fine, I will see if I
get any more doubts on this.

> If we go all the way to having only one message for interrupts, I
> suppose it does get a little uglier than I was hoping for, but it would still
> be doable: in this case, we could allow a flow like this on the eventq:
> 
> - driver requests edge interrupts

This over eventq and ..

> - (no event happened, so request remains pending)
> - driver queues a new request asking for IRQ_TYPE_NONE notification
>   in order to mask this line

This over controlq. Right ?

> - device replies to both requests saying no interrupt happened

Yes, that can work.

> Between this control flow and the version where set-type is part of
> set-direction, I would prefer the other option, but you already said
> that you don't like that one.

Yeah, I would like to keep this away from set-direction, which I am
already going to use for activate/deactivate :)

-- 
viresh