Merge tag 'rtc-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "There is nothing scary this cycle, mostly driver fixes and updates.

  The core fix has been in for a while and has been tested on multiple
  kernel revisions by multiple teams.

  Core:
   - Fix setting the alarm to the next expiring timer

  New drivers:
   - Mediatek MT7622 RTC
   - NXP PCF85363
   - Spreadtrum SC27xx PMIC RTC

  Drivers updates:
   - Use generic nvmem to expose the Non volatile ram for ds1305,
     ds1511, m48t86 and omap
   - abx80x: solve possible race condition at probe
   - armada38x: support trimming the RTC oscillator
   - at91rm9200: fix reading the alarm value at boot
   - ds1511: allow waking platform
   - m41t80: rework square wave output
   - pcf8523: support trimming the RTC oscillator
   - pcf8563: fix clock output rate
   - pl031: make interrupt optional
   - xgene: fix suspend/resume"

* tag 'rtc-4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (50 commits)
  dt-bindings: rtc: imxdi: Improve the bindings text
  rtc: sc27xx: Add Spreadtrum SC27xx PMIC RTC driver
  dt-bindings: rtc: Add Spreadtrum SC27xx RTC documentation
  rtc: at91rm9200: fix reading alarm value
  rtc: at91rm9200: stop calculating yday in at91_rtc_readalarm
  rtc: sysfs: Use time64_t variables to set time/alarm
  rtc: xgene: mark PM functions as __maybe_unused
  rtc: xgene: Fix suspend/resume
  rtc: pcf8563: don't alway enable the alarm
  rtc: pcf8563: fix output clock rate
  rtc: rx8010: Fix for incorrect return value
  rtc: rx8010: Specify correct address for RX8010_RESV31
  rtc: rx8010: Remove duplicate define
  rtc: m41t80: remove unneeded checks from m41t80_sqw_set_rate
  rtc: m41t80: avoid i2c read in m41t80_sqw_is_prepared
  rtc: m41t80: avoid i2c read in m41t80_sqw_recalc_rate
  rtc: m41t80: fix m41t80_sqw_round_rate return value
  rtc: m41t80: m41t80_sqw_set_rate should return 0 on success
  rtc: add support for NXP PCF85363 real-time clock
  rtc: omap: Support scratch registers
  ...

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 8cec9a02c0b8..672b192f8153 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -779,7 +779,7 @@ static int rtc_timer_enqueue(struct rtc_device *rtc, struct rtc_timer *timer)
 	}
 
 	timerqueue_add(&rtc->timerqueue, &timer->node);
-	if (!next) {
+	if (!next || ktime_before(timer->node.expires, next->expires)) {
 		struct rtc_wkalrm alarm;
 		int err;
 		alarm.time = rtc_ktime_to_tm(timer->node.expires);
@@ -1004,6 +1004,10 @@ int rtc_read_offset(struct rtc_device *rtc, long *offset)
  * to compensate for differences in the actual clock rate due to temperature,
  * the crystal, capacitor, etc.
  *
+ * The adjustment applied is as follows:
+ *   t = t0 * (1 + offset * 1e-9)
+ * where t0 is the measured length of 1 RTC second with offset = 0
+ *
  * Kernel interface to adjust an rtc clock offset.
  * Return 0 on success, or a negative number on error.
  * If the rtc offset is not setable (or not implemented), return -EINVAL