i2c: Bus drivers return -Errno not -1

Tighten error paths used by various i2c adapters (mostly x86) so
they return real fault/errno codes instead of a "-1" (which is
most often interpreted as "-EPERM").  Build tested, with eyeball
review.

One minor initial goal is to have adapters consistently return
the code "-ENXIO" when addressing a device doesn't get an ACK
response, at least in the probe paths where they are already
good at stifling related logspam.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 10 insertions, 12 deletions

diff --git a/drivers/i2c/busses/i2c-ali1535.c b/drivers/i2c/busses/i2c-ali1535.c
index f14372ac2fc5..c21e4d96382e 100644
--- a/drivers/i2c/busses/i2c-ali1535.c
+++ b/drivers/i2c/busses/i2c-ali1535.c
@@ -259,7 +259,7 @@ static int ali1535_transaction(struct i2c_adapter *adap)
 			dev_err(&adap->dev,
 				"SMBus reset failed! (0x%02x) - controller or "
 				"device on bus is probably hung\n", temp);
-			return -1;
+			return -EBUSY;
 		}
 	} else {
 		/* check and clear done bit */
@@ -281,12 +281,12 @@ static int ali1535_transaction(struct i2c_adapter *adap)
 
 	/* If the SMBus is still busy, we give up */
 	if (timeout >= MAX_TIMEOUT) {
-		result = -1;
+		result = -ETIMEDOUT;
 		dev_err(&adap->dev, "SMBus Timeout!\n");
 	}
 
 	if (temp & ALI1535_STS_FAIL) {
-		result = -1;
+		result = -EIO;
 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 	}
 
@@ -295,7 +295,7 @@ static int ali1535_transaction(struct i2c_adapter *adap)
 	 * do a printk.  This means that bus collisions go unreported.
 	 */
 	if (temp & ALI1535_STS_BUSERR) {
-		result = -1;
+		result = -ENXIO;
 		dev_dbg(&adap->dev,
 			"Error: no response or bus collision ADD=%02x\n",
 			inb_p(SMBHSTADD));
@@ -303,13 +303,13 @@ static int ali1535_transaction(struct i2c_adapter *adap)
 
 	/* haven't ever seen this */
 	if (temp & ALI1535_STS_DEV) {
-		result = -1;
+		result = -EIO;
 		dev_err(&adap->dev, "Error: device error\n");
 	}
 
 	/* check to see if the "command complete" indication is set */
 	if (!(temp & ALI1535_STS_DONE)) {
-		result = -1;
+		result = -ETIMEDOUT;
 		dev_err(&adap->dev, "Error: command never completed\n");
 	}
 
@@ -332,7 +332,7 @@ static int ali1535_transaction(struct i2c_adapter *adap)
 	return result;
 }
 
-/* Return -1 on error. */
+/* Return negative errno on error. */
 static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 			  unsigned short flags, char read_write, u8 command,
 			  int size, union i2c_smbus_data *data)
@@ -359,7 +359,7 @@ static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 	switch (size) {
 	case I2C_SMBUS_PROC_CALL:
 		dev_err(&adap->dev, "I2C_SMBUS_PROC_CALL not supported!\n");
-		result = -1;
+		result = -EOPNOTSUPP;
 		goto EXIT;
 	case I2C_SMBUS_QUICK:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
@@ -420,11 +420,9 @@ static s32 ali1535_access(struct i2c_adapter *adap, u16 addr,
 		break;
 	}
 
-	if (ali1535_transaction(adap)) {
-		/* Error in transaction */
-		result = -1;
+	result = ali1535_transaction(adap);
+	if (result)
 		goto EXIT;
-	}
 
 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI1535_QUICK)) {
 		result = 0;