diff options
| -rw-r--r-- | Documentation/i2c/writing-clients | 5 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core.c | 4 | ||||
| -rw-r--r-- | include/linux/i2c.h | 1 |
3 files changed, 6 insertions, 4 deletions
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 0a74603eb671..3219ee0dbfef 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -318,8 +318,9 @@ Plain I2C communication These routines read and write some bytes from/to a client. The client contains the i2c address, so you do not have to include it. The second parameter contains the bytes to read/write, the third the number of bytes -to read/write (must be less than the length of the buffer.) Returned is -the actual number of bytes read/written. +to read/write (must be less than the length of the buffer, also should be +less than 64k since msg.len is u16.) Returned is the actual number of bytes +read/written. int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num); diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 4131698008b9..3202a86f420e 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -1183,7 +1183,7 @@ EXPORT_SYMBOL(i2c_transfer); * i2c_master_send - issue a single I2C message in master transmit mode * @client: Handle to slave device * @buf: Data that will be written to the slave - * @count: How many bytes to write + * @count: How many bytes to write, must be less than 64k since msg.len is u16 * * Returns negative errno, or else the number of bytes written. */ @@ -1210,7 +1210,7 @@ EXPORT_SYMBOL(i2c_master_send); * i2c_master_recv - issue a single I2C message in master receive mode * @client: Handle to slave device * @buf: Where to store data read from slave - * @count: How many bytes to read + * @count: How many bytes to read, must be less than 64k since msg.len is u16 * * Returns negative errno, or else the number of bytes read. */ diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 476abd09c921..0a5da639b327 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -53,6 +53,7 @@ struct i2c_board_info; * on a bus (or read from them). Apart from two basic transfer functions to * transmit one message at a time, a more complex version can be used to * transmit an arbitrary number of messages without interruption. + * @count must be be less than 64k since msg.len is u16. */ extern int i2c_master_send(struct i2c_client *client, const char *buf, int count); |