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, 12 insertions, 11 deletions

diff --git a/drivers/i2c/busses/i2c-sis96x.c b/drivers/i2c/busses/i2c-sis96x.c
index dc235bb8e24d..29757b2e11dd 100644
--- a/drivers/i2c/busses/i2c-sis96x.c
+++ b/drivers/i2c/busses/i2c-sis96x.c
@@ -111,7 +111,7 @@ static int sis96x_transaction(int size)
                 /* check it again */
                 if (((temp = sis96x_read(SMB_CNT)) & 0x03) != 0x00) {
                         dev_dbg(&sis96x_adapter.dev, "Failed (0x%02x)\n", temp);
-                        return -1;
+                        return -EBUSY;
                 } else {
                         dev_dbg(&sis96x_adapter.dev, "Successful\n");
                 }
@@ -136,19 +136,19 @@ static int sis96x_transaction(int size)
         /* If the SMBus is still busy, we give up */
         if (timeout >= MAX_TIMEOUT) {
                 dev_dbg(&sis96x_adapter.dev, "SMBus Timeout! (0x%02x)\n", temp);
-                result = -1;
+                result = -ETIMEDOUT;
         }
 
         /* device error - probably missing ACK */
         if (temp & 0x02) {
                 dev_dbg(&sis96x_adapter.dev, "Failed bus transaction!\n");
-                result = -1;
+                result = -ENXIO;
         }
 
         /* bus collision */
         if (temp & 0x04) {
                 dev_dbg(&sis96x_adapter.dev, "Bus collision!\n");
-                result = -1;
+                result = -EIO;
         }
 
         /* Finish up by resetting the bus */
@@ -161,11 +161,12 @@ static int sis96x_transaction(int size)
         return result;
 }
 
-/* Return -1 on error. */
+/* Return negative errno on error. */
 static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
                          unsigned short flags, char read_write,
                          u8 command, int size, union i2c_smbus_data * data)
 {
+        int status;
 
         switch (size) {
         case I2C_SMBUS_QUICK:
@@ -203,17 +204,17 @@ static s32 sis96x_access(struct i2c_adapter * adap, u16 addr,
         case I2C_SMBUS_BLOCK_DATA:
                 /* TO DO: */
                 dev_info(&adap->dev, "SMBus block not implemented!\n");
-                return -1;
+                return -EOPNOTSUPP;
                 break;
 
         default:
-                dev_info(&adap->dev, "Unsupported I2C size\n");
-                return -1;
-                break;
+                dev_info(&adap->dev, "Unsupported SMBus operation\n");
+                return -EOPNOTSUPP;
         }
 
-        if (sis96x_transaction(size))
-                return -1;
+        status = sis96x_transaction(size);
+        if (status)
+                return status;
 
         if ((size != SIS96x_PROC_CALL) &&
                 ((read_write == I2C_SMBUS_WRITE) || (size == SIS96x_QUICK)))