linux-kernel - Re: [PATCH 2/2] regmap: irq: do not write mask register if it is not supported

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Date:	Thu, 14 Feb 2013 11:35:31 +0000
From:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
To:	Laxman Dewangan <ldewangan@...dia.com>
Cc:	"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 2/2] regmap: irq: do not write mask register if it is not
 supported

On Thu, Feb 14, 2013 at 04:36:08PM +0530, Laxman Dewangan wrote:
> On Wednesday 13 February 2013 07:50 PM, Mark Brown wrote:

> >>  	for (i = 0; i < d->chip->num_regs; i++) {
> >>+		if (!d->chip->mask_base)
> >>+			goto skip_mask_reg_update;

> >Why is this inside the loop?

You appear to have ignored this question.

> >I'd also expect us to return an error if a caller tries to enable or
> >disable an interrupt, or possibly to give different ops to the IRQ
> >subsystem, rather than just silently claim we did what we were asked.

> I tried to use regmap-irq for the gpio submodule and it has two sets
> of register:
> GPIOx_CNFG: bit[7:6] interrupt rising/falling.
> GPIO_INT_STS where each bit shows the interrupt status whether it
> occured or not.
> There is no mask register.

> In regmap-irq_thread() we see the interrupt status and compare
> against mask enable buffer wther this is enabled or not and
> accordingly call the handler.

> hence I am still require irq_mask()/irq_unmask() to reflect the mask
> with interrupt status and type for actually configuring the
> GPIOx_CNFG.

> if I remove the mask_buf at all then how do we tell the int_sts
> register is corresponding to which gpio handler?

This doesn't sound like something that should be open coded in
individual interrupt controller drivers, obviously it's a bit rubbish
that there's no way to enable or disable the interrupt but presumably
other hardware has the same "feature" and the IRQ subsystem ought to
understand it.

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