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, 9 deletions

diff --git a/drivers/i2c/busses/i2c-ali15x3.c b/drivers/i2c/busses/i2c-ali15x3.c
index 93bf87d70961..3d752561dc37 100644
--- a/drivers/i2c/busses/i2c-ali15x3.c
+++ b/drivers/i2c/busses/i2c-ali15x3.c
@@ -282,7 +282,7 @@ static int ali15x3_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 */
@@ -304,12 +304,12 @@ static int ali15x3_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 & ALI15X3_STS_TERM) {
-		result = -1;
+		result = -EIO;
 		dev_dbg(&adap->dev, "Error: Failed bus transaction\n");
 	}
 
@@ -320,7 +320,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
 	  This means that bus collisions go unreported.
 	*/
 	if (temp & ALI15X3_STS_COLL) {
-		result = -1;
+		result = -ENXIO;
 		dev_dbg(&adap->dev,
 			"Error: no response or bus collision ADD=%02x\n",
 			inb_p(SMBHSTADD));
@@ -328,7 +328,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
 
 	/* haven't ever seen this */
 	if (temp & ALI15X3_STS_DEV) {
-		result = -1;
+		result = -EIO;
 		dev_err(&adap->dev, "Error: device error\n");
 	}
 	dev_dbg(&adap->dev, "Transaction (post): STS=%02x, CNT=%02x, CMD=%02x, "
@@ -338,7 +338,7 @@ static int ali15x3_transaction(struct i2c_adapter *adap)
 	return result;
 }
 
-/* Return -1 on error. */
+/* Return negative errno on error. */
 static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
 		   unsigned short flags, char read_write, u8 command,
 		   int size, union i2c_smbus_data * data)
@@ -364,7 +364,7 @@ static s32 ali15x3_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");
-		return -1;
+		return -EOPNOTSUPP;
 	case I2C_SMBUS_QUICK:
 		outb_p(((addr & 0x7f) << 1) | (read_write & 0x01),
 		       SMBHSTADD);
@@ -421,8 +421,9 @@ static s32 ali15x3_access(struct i2c_adapter * adap, u16 addr,
 
 	outb_p(size, SMBHSTCNT);	/* output command */
 
-	if (ali15x3_transaction(adap))	/* Error in transaction */
-		return -1;
+	temp = ali15x3_transaction(adap);
+	if (temp)
+		return temp;
 
 	if ((read_write == I2C_SMBUS_WRITE) || (size == ALI15X3_QUICK))
 		return 0;