summaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
Diffstat (limited to 'drivers')
-rw-r--r--drivers/i2c/algos/i2c-algo-bit.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 260c5d70b0b4..35812823787b 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -357,10 +357,26 @@ static int sendbytes(struct i2c_adapter *i2c_adap, struct i2c_msg *msg)
count--;
temp++;
wrcount++;
- } else { /* arbitration or no acknowledge */
- dev_err(&i2c_adap->dev, "sendbytes: error - bailout.\n");
- return (retval<0)? retval : -EFAULT;
- /* got a better one ?? */
+
+ /* A slave NAKing the master means the slave didn't like
+ * something about the data it saw. For example, maybe
+ * the SMBus PEC was wrong.
+ */
+ } else if (retval == 0) {
+ dev_err(&i2c_adap->dev, "sendbytes: NAK bailout.\n");
+ return -EIO;
+
+ /* Timeout; or (someday) lost arbitration
+ *
+ * FIXME Lost ARB implies retrying the transaction from
+ * the first message, after the "winning" master issues
+ * its STOP. As a rule, upper layer code has no reason
+ * to know or care about this ... it is *NOT* an error.
+ */
+ } else {
+ dev_err(&i2c_adap->dev, "sendbytes: error %d\n",
+ retval);
+ return retval;
}
}
return wrcount;