4 files changed, 28 insertions, 17 deletions

diff --git a/drivers/rtc/rtc-mxc_v2.c b/drivers/rtc/rtc-mxc_v2.c
index 45c7366b7..c16aa4a38 100644
--- a/drivers/rtc/rtc-mxc_v2.c
+++ b/drivers/rtc/rtc-mxc_v2.c
@@ -335,8 +335,10 @@ static int mxc_rtc_probe(struct platform_device *pdev)
 	}
 
 	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
-	if (IS_ERR(pdata->rtc))
+	if (IS_ERR(pdata->rtc)) {
+		clk_disable_unprepare(pdata->clk);
 		return PTR_ERR(pdata->rtc);
+	}
 
 	pdata->rtc->ops = &mxc_rtc_ops;
 	pdata->rtc->range_max = U32_MAX;
diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
index e03104b73..a5455b2a3 100644
--- a/drivers/rtc/rtc-pm8xxx.c
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -229,7 +229,6 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
 	int rc, i;
 	u8 value[NUM_8_BIT_RTC_REGS];
-	unsigned int ctrl_reg;
 	unsigned long secs, irq_flags;
 	struct pm8xxx_rtc *rtc_dd = dev_get_drvdata(dev);
 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
@@ -241,6 +240,11 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 		secs >>= 8;
 	}
 
+	rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+				regs->alarm_en, 0);
+	if (rc)
+		return rc;
+
 	spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
 
 	rc = regmap_bulk_write(rtc_dd->regmap, regs->alarm_rw, value,
@@ -250,19 +254,11 @@ static int pm8xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 		goto rtc_rw_fail;
 	}
 
-	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
-	if (rc)
-		goto rtc_rw_fail;
-
-	if (alarm->enabled)
-		ctrl_reg |= regs->alarm_en;
-	else
-		ctrl_reg &= ~regs->alarm_en;
-
-	rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
-	if (rc) {
-		dev_err(dev, "Write to RTC alarm control register failed\n");
-		goto rtc_rw_fail;
+	if (alarm->enabled) {
+		rc = regmap_update_bits(rtc_dd->regmap, regs->alarm_ctrl,
+					regs->alarm_en, regs->alarm_en);
+		if (rc)
+			goto rtc_rw_fail;
 	}
 
 	dev_dbg(dev, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
diff --git a/drivers/rtc/rtc-snvs.c b/drivers/rtc/rtc-snvs.c
index 3cf011e12..b1e13f287 100644
--- a/drivers/rtc/rtc-snvs.c
+++ b/drivers/rtc/rtc-snvs.c
@@ -32,6 +32,14 @@
 #define SNVS_LPPGDR_INIT	0x41736166
 #define CNTR_TO_SECS_SH		15
 
+/* The maximum RTC clock cycles that are allowed to pass between two
+ * consecutive clock counter register reads. If the values are corrupted a
+ * bigger difference is expected. The RTC frequency is 32kHz. With 320 cycles
+ * we end at 10ms which should be enough for most cases. If it once takes
+ * longer than expected we do a retry.
+ */
+#define MAX_RTC_READ_DIFF_CYCLES	320
+
 struct snvs_rtc_data {
 	struct rtc_device *rtc;
 	struct regmap *regmap;
@@ -56,6 +64,7 @@ static u64 rtc_read_lpsrt(struct snvs_rtc_data *data)
 static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
 {
 	u64 read1, read2;
+	s64 diff;
 	unsigned int timeout = 100;
 
 	/* As expected, the registers might update between the read of the LSB
@@ -66,7 +75,8 @@ static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
 	do {
 		read2 = read1;
 		read1 = rtc_read_lpsrt(data);
-	} while (read1 != read2 && --timeout);
+		diff = read1 - read2;
+	} while (((diff < 0) || (diff > MAX_RTC_READ_DIFF_CYCLES)) && --timeout);
 	if (!timeout)
 		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
 
@@ -78,13 +88,15 @@ static u32 rtc_read_lp_counter(struct snvs_rtc_data *data)
 static int rtc_read_lp_counter_lsb(struct snvs_rtc_data *data, u32 *lsb)
 {
 	u32 count1, count2;
+	s32 diff;
 	unsigned int timeout = 100;
 
 	regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
 	do {
 		count2 = count1;
 		regmap_read(data->regmap, data->offset + SNVS_LPSRTCLR, &count1);
-	} while (count1 != count2 && --timeout);
+		diff = count1 - count2;
+	} while (((diff < 0) || (diff > MAX_RTC_READ_DIFF_CYCLES)) && --timeout);
 	if (!timeout) {
 		dev_err(&data->rtc->dev, "Timeout trying to get valid LPSRT Counter read\n");
 		return -ETIMEDOUT;
diff --git a/drivers/rtc/rtc-st-lpc.c b/drivers/rtc/rtc-st-lpc.c
index bee75ca7f..e66439b62 100644
--- a/drivers/rtc/rtc-st-lpc.c
+++ b/drivers/rtc/rtc-st-lpc.c
@@ -249,6 +249,7 @@ static int st_rtc_probe(struct platform_device *pdev)
 
 	rtc->clkrate = clk_get_rate(rtc->clk);
 	if (!rtc->clkrate) {
+		clk_disable_unprepare(rtc->clk);
 		dev_err(&pdev->dev, "Unable to fetch clock rate\n");
 		return -EINVAL;
 	}