linux-kernel - Re: [PATCH v2] rtc: imxdi: use the security violation interrupt

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Message-ID: <20161221230638.GA12514@reykholt.kaiser.cx>
Date:   Thu, 22 Dec 2016 00:06:38 +0100
From:   Martin Kaiser <martin@...ser.cx>
To:     Lucas Stach <l.stach@...gutronix.de>
Cc:     Alexandre Belloni <alexandre.belloni@...e-electrons.com>,
        Shawn Guo <shawnguo@...nel.org>,
        Sascha Hauer <kernel@...gutronix.de>,
        Juergen Borleis <jbe@...gutronix.de>,
        Fabio Estevam <fabio.estevam@....com>,
        linux-kernel@...r.kernel.org, rtc-linux@...glegroups.com
Subject: Re: [PATCH v2] rtc: imxdi: use the security violation interrupt

Hello Lucas,

thanks for taking the time to review my patch.

Thus wrote Lucas Stach (l.stach@...gutronix.de):

> > diff --git a/drivers/rtc/rtc-imxdi.c b/drivers/rtc/rtc-imxdi.c
> > index 67b56b8..ec6077a0 100644
> > --- a/drivers/rtc/rtc-imxdi.c
> > +++ b/drivers/rtc/rtc-imxdi.c
> > @@ -109,6 +109,7 @@
> >   * @rtc: pointer to rtc struct
> >   * @ioaddr: IO registers pointer
> >   * @irq: dryice normal interrupt
> > + * @sec_irq: dryice security violation interrupt

> This isn't used outside the probe routine, so doesn't need to be saved
> in the driver data.

The same goes for imxdi->irq, I made this a local variable as well.

> > +	rc = devm_request_irq(&pdev->dev, imxdi->sec_irq, dryice_sec_irq,
> > +			IRQF_SHARED, pdev->name, imxdi);
> > +	if (rc) {
> > +		dev_warn(&pdev->dev, "security violation interrupt not available.\n");
> > +		/* this is not an error, see above */
> > +	}
> > +
> Please just fold this into the "if (rc > 0)" path above.

Are you sure that this would be correct?

My understanding is that we should mask the interrupts by writing 0 into
DIER and set the DryIce to a sane state in di_handle_state() before we
install interrupt handlers.

Best regards,
Martin