1 files changed, 44 insertions, 16 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index a6ad32bc0a96..2efa56c5ff2c 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1312,6 +1312,37 @@ module_exit(i2c_exit);
  */
 
 /**
+ * __i2c_transfer - unlocked flavor of i2c_transfer
+ * @adap: Handle to I2C bus
+ * @msgs: One or more messages to execute before STOP is issued to
+ *	terminate the operation; each message begins with a START.
+ * @num: Number of messages to be executed.
+ *
+ * Returns negative errno, else the number of messages executed.
+ *
+ * Adapter lock must be held when calling this function. No debug logging
+ * takes place. adap->algo->master_xfer existence isn't checked.
+ */
+int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	unsigned long orig_jiffies;
+	int ret, try;
+
+	/* Retry automatically on arbitration loss */
+	orig_jiffies = jiffies;
+	for (ret = 0, try = 0; try <= adap->retries; try++) {
+		ret = adap->algo->master_xfer(adap, msgs, num);
+		if (ret != -EAGAIN)
+			break;
+		if (time_after(jiffies, orig_jiffies + adap->timeout))
+			break;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(__i2c_transfer);
+
+/**
  * i2c_transfer - execute a single or combined I2C message
  * @adap: Handle to I2C bus
  * @msgs: One or more messages to execute before STOP is issued to
@@ -1325,8 +1356,7 @@ module_exit(i2c_exit);
  */
 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 {
-	unsigned long orig_jiffies;
-	int ret, try;
+	int ret;
 
 	/* REVISIT the fault reporting model here is weak:
 	 *
@@ -1364,15 +1394,7 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
 			i2c_lock_adapter(adap);
 		}
 
-		/* Retry automatically on arbitration loss */
-		orig_jiffies = jiffies;
-		for (ret = 0, try = 0; try <= adap->retries; try++) {
-			ret = adap->algo->master_xfer(adap, msgs, num);
-			if (ret != -EAGAIN)
-				break;
-			if (time_after(jiffies, orig_jiffies + adap->timeout))
-				break;
-		}
+		ret = __i2c_transfer(adap, msgs, num);
 		i2c_unlock_adapter(adap);
 
 		return ret;
@@ -2122,7 +2144,7 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
 	int try;
 	s32 res;
 
-	flags &= I2C_M_TEN | I2C_CLIENT_PEC;
+	flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB;
 
 	if (adapter->algo->smbus_xfer) {
 		i2c_lock_adapter(adapter);
@@ -2140,11 +2162,17 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
 				break;
 		}
 		i2c_unlock_adapter(adapter);
-	} else
-		res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
-					      command, protocol, data);
 
-	return res;
+		if (res != -EOPNOTSUPP || !adapter->algo->master_xfer)
+			return res;
+		/*
+		 * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't
+		 * implement native support for the SMBus operation.
+		 */
+	}
+
+	return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write,
+				       command, protocol, data);
 }
 EXPORT_SYMBOL(i2c_smbus_xfer);