Merge tag 'irqchip-4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/urgent

Pull irqchip updates for 4.16-rc2 from Marc Zyngier

 - A MIPS GIC fix for spurious, masked interrupts
 - A fix for a subtle IPI bug in GICv3
 - Do not probe GICv3 ITSs that are marked as disabled
 - Multi-MSI support for GICv2m
 - Various cleanups

1 files changed, 26 insertions, 9 deletions

diff --git a/drivers/misc/ds1682.c b/drivers/misc/ds1682.c
index 7231260ac287..98a921ea9ee8 100644
--- a/drivers/misc/ds1682.c
+++ b/drivers/misc/ds1682.c
@@ -59,25 +59,42 @@ static ssize_t ds1682_show(struct device *dev, struct device_attribute *attr,
 {
 	struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
 	struct i2c_client *client = to_i2c_client(dev);
-	__le32 val = 0;
+	unsigned long long val, check;
+	__le32 val_le = 0;
 	int rc;
 
 	dev_dbg(dev, "ds1682_show() called on %s\n", attr->attr.name);
 
 	/* Read the register */
 	rc = i2c_smbus_read_i2c_block_data(client, sattr->index, sattr->nr,
-					   (u8 *) & val);
+					   (u8 *)&val_le);
 	if (rc < 0)
 		return -EIO;
 
-	/* Special case: the 32 bit regs are time values with 1/4s
-	 * resolution, scale them up to milliseconds */
-	if (sattr->nr == 4)
-		return sprintf(buf, "%llu\n",
-			((unsigned long long)le32_to_cpu(val)) * 250);
+	val = le32_to_cpu(val_le);
+
+	if (sattr->index == DS1682_REG_ELAPSED) {
+		int retries = 5;
+
+		/* Detect and retry when a tick occurs mid-read */
+		do {
+			rc = i2c_smbus_read_i2c_block_data(client, sattr->index,
+							   sattr->nr,
+							   (u8 *)&val_le);
+			if (rc < 0 || retries <= 0)
+				return -EIO;
+
+			check = val;
+			val = le32_to_cpu(val_le);
+			retries--;
+		} while (val != check && val != (check + 1));
+	}
 
-	/* Format the output string and return # of bytes */
-	return sprintf(buf, "%li\n", (long)le32_to_cpu(val));
+	/* Format the output string and return # of bytes
+	 * Special case: the 32 bit regs are time values with 1/4s
+	 * resolution, scale them up to milliseconds
+	 */
+	return sprintf(buf, "%llu\n", (sattr->nr == 4) ? (val * 250) : val);
 }
 
 static ssize_t ds1682_store(struct device *dev, struct device_attribute *attr,