Re: [PATCH 03/12] rtc: omap: fix class-device registration

Felipe Balbi
2014-10-13T15:57:07Z

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Hi,

On Sat, Oct 11, 2014 at 11:59:47AM +0200, Johan Hovold wrote:
> > > @@ -450,14 +441,14 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
> > >
> > > /* handle periodic and alarm irqs */
> > > if (devm_request_irq(&pdev->dev, omap_rtc_timer, rtc_irq, 0,
> > > - dev_name(&rtc->dev), rtc)) {
> > > + dev_name(&pdev->dev), pdev)) {
> > > pr_debug("%s: RTC timer interrupt IRQ%d already claimed\n",
> > > pdev->name, omap_rtc_timer);
> > > goto fail0;
> > > }
> > > if ((omap_rtc_timer != omap_rtc_alarm) &&
> > > (devm_request_irq(&pdev->dev, omap_rtc_alarm, rtc_irq, 0,
> > > - dev_name(&rtc->dev), rtc))) {
> > > + dev_name(&pdev->dev), pdev))) {
> >
> > i don't get it. Why pass pdev as cookie when all you need is rtc ?
> > Doesn't sound very good to me. Also, IRQ handler *must* be registered
> > only after RTC is registered. That's because if you request an IRQ here,
> > you could already have a pending interrupt and since you won't have a
> > valid rtc pointer you won't be able to clear the interrupt line.
>
> We don't need the class device (rtc pointer) to clear the interrupt
> line. The iomem base is enough, and that is static until Lokesh adds the
> struct omap_rtc_dev abstraction. Then we pass that as the cookie.

I wonder how that patch will look like ;-)

> And all RTC interrupts have been disabled, and pending interrupts
> cleared before registering the handlers so that should not be a problem.
>
> To the contrary, once the class device has been registered user-space
> could enable interrupts at any time and that is why everything should
> have been set up before.

alright, got it. Thanks

--
balbi

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