Commit 3e74ddaa authored by Alexandre Belloni's avatar Alexandre Belloni
Browse files

rtc: disallow update interrupts when time is invalid 

Never enable update interrupts when the time set on the rtc is invalid.
In that case, also avoid enabling the emulation because it will fail for
the same reason.

Link: https://lore.kernel.org/r/20191021155631.3342-2-alexandre.belloni@bootlin.com
Link: https://lore.kernel.org/r/CA+ASDXMarBG5C1Kz42B9i_iVZ1=i6GgH9Yja2cdmSueKD_As_g@mail.gmail.com


Reported-by: default avatarJeffy Chen <jeffy.chen@rock-chips.com>
Reported-by: default avatarBrian Norris <briannorris@chromium.org>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 7e7c005b

drivers/rtc/interface.c

+14 −2
Original line number Diff line number Diff line
@@ -545,7 +545,7 @@ EXPORT_SYMBOL_GPL(rtc_alarm_irq_enable); 


int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled)

{

	int err;

	int rc = 0, err;



	err = mutex_lock_interruptible(&rtc->ops_lock);

	if (err)
@@ -570,7 +570,9 @@ int rtc_update_irq_enable(struct rtc_device *rtc, unsigned int enabled) 
		struct rtc_time tm;

		ktime_t now, onesec;



		__rtc_read_time(rtc, &tm);

		rc = __rtc_read_time(rtc, &tm);

		if (rc)

			goto out;

		onesec = ktime_set(1, 0);

		now = rtc_tm_to_ktime(tm);

		rtc->uie_rtctimer.node.expires = ktime_add(now, onesec);
@@ -582,6 +584,16 @@ 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

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