Re: [rtc-linux] [PATCH 1/2] rtc: rtc-lpc32xx: Introduce RTC driverfor the LPC32XX SoC

From: Uwe Kleine-König
Date: Tue Aug 10 2010 - 08:01:11 EST


Hi Wolfram,

> > + retval = request_irq(rtc->irq, lpc32xx_rtc_alarm_interrupt,
> > + IRQF_DISABLED, "rtcalarm", rtc);
> > + if (retval < 0) {
> > + dev_err(&pdev->dev, "Can't request interrupt\n");
> > + goto err_free_irq;
> > + }
>
> I saw that a number of rtc-drivers register their irq after they
> register the device. I wonder if this is OK here? Couldn't it happen
> that after rtc_device_register() there is a preemption and another
> process could set the alarm? Then there is a race between interrupts
> already enabled and no handler available, no?
If you do it the other way around the irq might trigger and the handler
reports an irq for a device that doesn't exist yet.

Best regards
Uwe

--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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