Re: [PATCH 3/3] rtc: rtc_update_irq_enable: rework UIE emulation

From: Łukasz Stelmach
Date: Fri Apr 02 2021 - 06:28:20 EST


It was <2021-03-30 wto 02:03>, when Alexandre Belloni wrote:
> Now that the core is aware of whether alarms are available, it is possible
> to decide whether UIE emulation is required before actually trying to set
> the alarm.
>
> This greatly simplifies rtc_update_irq_enable because there is now only one
> error value to track and is not relying on the return value of
> __rtc_set_alarm anymore.
>
> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
> ---
> drivers/rtc/interface.c | 28 +++++++---------------------
> 1 file changed, 7 insertions(+), 21 deletions(-)
>

Tested-by: Łukasz Stelmach <l.stelmach@xxxxxxxxxxx>

> diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
> index dcb34c73319e..b162964d2b39 100644
> --- a/drivers/rtc/interface.c
> +++ b/drivers/rtc/interface.c
> @@ -561,8 +561,12 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> if (rtc->uie_rtctimer.enabled == enabled)
> goto out;
>
> - if (rtc->uie_unsupported) {
> + if (rtc->uie_unsupported || !test_bit(RTC_FEATURE_ALARM, rtc->features)) {
> +#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
> + err = rtc_dev_update_irq_enable_emul(rtc, enabled);
> +#else
> err = -EINVAL;
> +#endif
> goto out;
> }
>
> @@ -570,8 +574,8 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> struct rtc_time tm;
> ktime_t now, onesec;
>
> - rc = __rtc_read_time(rtc, &tm);
> - if (rc)
> + err = __rtc_read_time(rtc, &tm);
> + if (err)
> goto out;
> onesec = ktime_set(1, 0);
> now = rtc_tm_to_ktime(tm);
> @@ -585,24 +589,6 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)
> out:
> mutex_unlock(&rtc->ops_lock);
>
> - /*
> - * __rtc_read_time() failed, this probably means that the RTC time has
> - * never been set or less probably there is a transient error on the
> - * bus. In any case, avoid enabling emulation has this will fail when
> - * reading the time too.
> - */
> - if (rc)
> - return rc;
> -
> -#ifdef CONFIG_RTC_INTF_DEV_UIE_EMUL
> - /*
> - * Enable emulation if the driver returned -EINVAL to signal that it has
> - * been configured without interrupts or they are not available at the
> - * moment.
> - */
> - if (err == -EINVAL)
> - err = rtc_dev_update_irq_enable_emul(rtc, enabled);
> -#endif
> return err;
> }
> EXPORT_SYMBOL_GPL(rtc_update_irq_enable);

--
Łukasz Stelmach
Samsung R&D Institute Poland
Samsung Electronics

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