[rtc-linux] Re: [RFC PATCH v2 1/2] rtc-cmos: Clear interrupt flag if alarm time is

[Alexandre Belloni <alexandre.belloni@free-electrons.com>]

On 26/06/2015 at 14:01:48 +0800, Huang Adrian wrote :
> I created the following patch based on your suggestion. Does it looks good
> to you? If it does, I'll prepare v3 for testing. Thanks in advance.
> 

Seems good to me.

> diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
> index a82556a..f8900aa 100644
> --- a/drivers/rtc/rtc-cmos.c
> +++ b/drivers/rtc/rtc-cmos.c
> @@ -51,6 +51,7 @@ struct cmos_rtc {
>         struct device           *dev;
>         int                     irq;
>         struct resource         *iomem;
> +       time64_t                alarm_expires;
> 
>         void                    (*wake_on)(struct device *);
>         void                    (*wake_off)(struct device *);
> @@ -377,6 +378,8 @@ static int cmos_set_alarm(struct device *dev,
> struct rtc_wkalrm *t)
> 
>         spin_unlock_irq(&rtc_lock);
> 
> +       cmos->alarm_expires = rtc_tm_to_time64(&t->time);
> +
>         return 0;
>  }
> 
> @@ -860,6 +863,52 @@ static void __exit cmos_do_remove(struct device *dev)
>         cmos->dev = NULL;
>  }
> 
> +static int cmos_aie_poweroff(struct device *dev)
> +{
> +       struct cmos_rtc *cmos = dev_get_drvdata(dev);
> +       struct rtc_time now;
> +       time64_t t_now;
> +       int retval = 0;
> +       unsigned char rtc_control;
> +
> +       if (!cmos->alarm_expires)
> +               return -EINVAL;
> +
> +       spin_lock_irq(&rtc_lock);
> +       rtc_control = CMOS_READ(RTC_CONTROL);
> +       spin_unlock_irq(&rtc_lock);
> +
> +       /* We only care about the situation where AIE is disabled. */
> +       if (rtc_control & RTC_AIE)
> +               return -EBUSY;
> +
> +       cmos_read_time(dev, &now);
> +       t_now = rtc_tm_to_time64(&now);
> +
> +       /*
> +        * When enabling "RTC wake-up" in BIOS setup, the machine reboots
> +        * automatically right after shutdown on some buggy boxes.
> +        * This automatic rebooting issue won't happen when the alarm
> +        * time is larger than now+1 seconds.
> +        *
> +        * If the alarm time is equal to now+1 seconds, the issue can be
> +        * prevented by cancelling the alarm.
> +        */
> +       if (cmos->alarm_expires == t_now + 1) {
> +               struct rtc_wkalrm alarm;
> +               int err;
> +
> +               /* Cancel the AIE timer by configuring the past time. */
> +               rtc_time64_to_tm(t_now - 1, &alarm.time);
> +               alarm.enabled = 0;
> +               retval = cmos_set_alarm(dev, &alarm);
> +       } else if (cmos->alarm_expires > t_now + 1) {
> +               retval = -EBUSY;
> +       }
> +
> +       return retval;
> +}
> +
>  #ifdef CONFIG_PM
> 
>  static int cmos_suspend(struct device *dev)
> @@ -1094,8 +1143,12 @@ static void cmos_pnp_shutdown(struct pnp_dev *pnp)
>         struct device *dev = &pnp->dev;
>         struct cmos_rtc *cmos = dev_get_drvdata(dev);
> 
> -       if (system_state == SYSTEM_POWER_OFF && !cmos_poweroff(dev))
> -               return;
> +       if (system_state == SYSTEM_POWER_OFF) {
> +               int retval = cmos_poweroff(dev);
> +
> +               if (cmos_aie_poweroff(dev) < 0 && !retval)
> +                       return;
> +       }
> 
>         cmos_do_shutdown(cmos->irq);
>  }
> @@ -1200,8 +1253,12 @@ static void cmos_platform_shutdown(struct
> platform_device *pdev)
>         struct device *dev = &pdev->dev;
>         struct cmos_rtc *cmos = dev_get_drvdata(dev);
> 
> -       if (system_state == SYSTEM_POWER_OFF && !cmos_poweroff(dev))
> -               return;
> +       if (system_state == SYSTEM_POWER_OFF) {
> +               int retval = cmos_poweroff(dev);
> +
> +               if (cmos_aie_poweroff(dev) < 0 && !retval)
> +                       return;
> +       }
> 
>         cmos_do_shutdown(cmos->irq);
>  }
> --
> 1.9.1

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com

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