Re: [PATCH v3] regmap: regmap-irq/gpio-max77620: add level-irq support

From: Matti Vaittinen
Date: Wed Jan 02 2019 - 02:43:12 EST

On Mon, Dec 31, 2018 at 07:11:27PM +0000, Mark Brown wrote:
> On Fri, Dec 28, 2018 at 10:05:33AM +0200, Matti Vaittinen wrote:
> > Last night - just when I was about to get some sleep - it stroke me. I
> > think the correct thing to do would be leaving the irq_set_type to NULL
> > for those IRQ chips which do not support type setting. If we do that,
> > then the irq core will take care of situations where user requests type
> > setting but the chip does not support it. Which means the regmap-irq
> > would be no different from any other irq chip where type setting is not
> > supported.
> Yes, this is the best fix - let the framework handle things properly.
> We'll need a second set of operations and to select which to use based
> on having type information but that's fine.
> > So at the cost of removing "const" from regmap_irq_chip we could do:
> ...
> > Mark, Geert, what do you think? (And maybe same for the .irq_set_wake -
> > but I did omit this as I have never looked at the wake functionality
> > before).
> We need a separate struct as otherwise if there's multiple devices with
> regmap irq_chip implementations then they'll collide with each other

Right. I must admit I didn't notice this! I was about to make a nasty
error there...

> otherwise I like this approach (or we could copy the irq_chip struct
> when registering and then modify which is going to scale a bit better -

I am really not a fan of dynamic allocation - I'd rather had static
structs with different set of operations. But I admit I can't think of a
sane system where we would have more than few regmap_irq controllers so
memory consumption of allocating new structs is hardly an issue here.

> you're probably right that we need to do the same thing for the wake
> configuration. I'll still look at applying your patch as a temporary
> fix though.

Thanks Mark. I try to cook a patch with copying of struct irq_chip still
at this week but I wont rush it (I have some other topics under work) as
the regression should be fixed by the other patch.

Matti Vaittinen

Matti Vaittinen
ROHM Semiconductors

~~~ "I don't think so," said Rene Descartes. Just then, he vanished ~~~