linux-kernel - RE: [PATCH] alarmtimer: Fix rebind failure

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Message-ID: <OS0PR01MB592280D33C80AACADEB5958886F9A@OS0PR01MB5922.jpnprd01.prod.outlook.com>
Date:   Wed, 20 Sep 2023 13:31:10 +0000
From:   Biju Das <biju.das.jz@...renesas.com>
To:     Alexandre Belloni <alexandre.belloni@...tlin.com>
CC:     Thomas Gleixner <tglx@...utronix.de>,
        Alessandro Zummo <a.zummo@...ertech.it>,
        John Stultz <jstultz@...gle.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Geert Uytterhoeven <geert+renesas@...der.be>,
        Biju Das <biju.das.au@...il.com>,
        "linux-rtc@...r.kernel.org" <linux-rtc@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-renesas-soc@...r.kernel.org" 
        <linux-renesas-soc@...r.kernel.org>
Subject: RE: [PATCH] alarmtimer: Fix rebind failure

Hi Alexandre Belloni,

> Subject: Re: [PATCH] alarmtimer: Fix rebind failure
> 
> On 20/09/2023 12:59:35+0100, Biju Das wrote:
> > The resources allocated in alarmtimer_rtc_add_device() are not freed
> > leading to re-bind failure for the endpoint driver. Fix this issue by
> > adding alarmtimer_rtc_remove_device().
> >
> > Signed-off-by: Biju Das <biju.das.jz@...renesas.com>
> > ---
> > This issue is found while adding irq support for built in RTC found on
> > Renesas PMIC RAA215300 device. This issue should present on all RTC
> > drivers which calls device_init_wakeup() in probe().
> > ---
> >  kernel/time/alarmtimer.c | 20 ++++++++++++++++++++
> >  1 file changed, 20 insertions(+)
> >
> > diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index
> > 8d9f13d847f0..592668136bb5 100644
> > --- a/kernel/time/alarmtimer.c
> > +++ b/kernel/time/alarmtimer.c
> > @@ -61,6 +61,7 @@ static DEFINE_SPINLOCK(freezer_delta_lock);
> >  /* rtc timer and device for setting alarm wakeups at suspend */
> >  static struct rtc_timer		rtctimer;
> >  static struct rtc_device	*rtcdev;
> > +static struct platform_device	*rtc_pdev;
> 
> This is the alarmtimer pdev, not the RTC one, right?

Yes, it is alarmtimer pdev.

Cheers,
Biju

> 
> >  static DEFINE_SPINLOCK(rtcdev_lock);
> >
> >  /**
> > @@ -109,6 +110,7 @@ static int alarmtimer_rtc_add_device(struct device
> *dev)
> >  		}
> >
> >  		rtcdev = rtc;
> > +		rtc_pdev = pdev;
> >  		/* hold a reference so it doesn't go away */
> >  		get_device(dev);
> >  		pdev = NULL;
> > @@ -123,6 +125,23 @@ static int alarmtimer_rtc_add_device(struct device
> *dev)
> >  	return ret;
> >  }
> >
> > +static void alarmtimer_rtc_remove_device(struct device *dev) {
> > +	struct rtc_device *rtc = to_rtc_device(dev);
> > +
> > +	if (rtc_pdev) {
> > +		module_put(rtc->owner);
> > +		if (device_may_wakeup(rtc->dev.parent))
> > +			device_init_wakeup(&rtc_pdev->dev, false);
> > +
> > +		platform_device_unregister(rtc_pdev);
> > +		put_device(dev);
> > +	}
> > +
> > +	rtcdev = NULL;
> > +	rtc_pdev = NULL;
> > +}
> > +
> >  static inline void alarmtimer_rtc_timer_init(void)  {
> >  	rtc_timer_init(&rtctimer, NULL, NULL); @@ -130,6 +149,7 @@ static
> > inline void alarmtimer_rtc_timer_init(void)
> >
> >  static struct class_interface alarmtimer_rtc_interface = {
> >  	.add_dev = &alarmtimer_rtc_add_device,
> > +	.remove_dev = &alarmtimer_rtc_remove_device,
> >  };
> >
> >  static int alarmtimer_rtc_interface_setup(void)
> > --
> > 2.25.1
> >
> 
> --
>