Re: [PATCH v1] gpio: dwapb: mask/unmask IRQ when disable/enable it

[luojiaxing]

On 2020/12/7 2:50, Marc Zyngier wrote:
> On 2020-12-06 15:02, Linus Walleij wrote:
> > On Sat, Dec 5, 2020 at 11:15 PM Serge Semin <fancer.lancer@xxxxxxxxx> 
> > wrote:
> >
> > > Hmm, that sounds like a problem, but the explanation is a bit unclear
> > > to me. AFAICS you are saying that the only callbacks which are
> > > called during the IRQ request/release are the irq_enable(), right? If
> > > so then the only reason why we haven't got a problem reported due to
> > > that so far is that the IRQs actually unmasked by default.
> >
> > What we usually do in cases like that (and I have discussed this
> > with tglx in the past I think) is to simply mask off all IRQs in 
> > probe().
> > Then they will be unmasked when requested by drivers.
> >
> > See e.g. gpio-pl061 that has this line in probe():
> > writeb(0, pl061->base + GPIOIE); /* disable irqs */
>
> This should definitely be the default behaviour. The code code
> expects all interrupt sources to be masked until actively enabled,
> usually with the IRQ being requested.


I think this patch is used for that purpose. I do two things in 
irq_enable(): unmask irq and then enable IRQ;

and for irq_disable(), it's similar; mask IRQ then disable it.


Thanks

Jiaxing


> Thanks,
>
>         M.