i2c_smbus_read_block_data() returns negative errno else the number of data bytes in the slave's response.
Checking for error not null means the function always fails if the device answers properly. So given that we read 3 bytes and access those, better check that we actually read those 3 bytes. Signed-off-by: Benjamin Tissoires <[email protected]> --- drivers/input/mouse/elan_i2c_smbus.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/input/mouse/elan_i2c_smbus.c b/drivers/input/mouse/elan_i2c_smbus.c index cb6aecb..9b43b55 100644 --- a/drivers/input/mouse/elan_i2c_smbus.c +++ b/drivers/input/mouse/elan_i2c_smbus.c @@ -226,7 +226,7 @@ static int elan_smbus_get_max(struct i2c_client *client, u8 val[3]; error = i2c_smbus_read_block_data(client, ETP_SMBUS_RANGE_CMD, val); - if (error) { + if (error != 3) { dev_err(&client->dev, "failed to get dimensions: %d\n", error); return error; } @@ -245,7 +245,7 @@ static int elan_smbus_get_resolution(struct i2c_client *client, error = i2c_smbus_read_block_data(client, ETP_SMBUS_RESOLUTION_CMD, val); - if (error) { + if (error != 3) { dev_err(&client->dev, "failed to get resolution: %d\n", error); return error; } @@ -265,7 +265,7 @@ static int elan_smbus_get_num_traces(struct i2c_client *client, error = i2c_smbus_read_block_data(client, ETP_SMBUS_XY_TRACENUM_CMD, val); - if (error) { + if (error != 3) { dev_err(&client->dev, "failed to get trace info: %d\n", error); return error; } -- 2.7.4
