Remove racey i2c_smbus_read_byte() calls in measurement
reading function with an single i2c_transfer.
Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
---
drivers/iio/chemical/vz89x.c | 33 +++++++++++++++++++++++----------
1 file changed, 23 insertions(+), 10 deletions(-)
diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
index 11e59a5..c03f988 100644
--- a/drivers/iio/chemical/vz89x.c
+++ b/drivers/iio/chemical/vz89x.c
@@ -100,27 +100,40 @@ static int vz89x_measurement_is_valid(struct vz89x_data *data)
return !!(data->buffer[VZ89X_REG_MEASUREMENT_SIZE - 1] > 0);
}
+static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
+{
+ struct i2c_client *client = data->client;
+ struct i2c_msg msg[2];
+ int ret;
+ u8 buf[3] = { cmd, 0, 0};
+
+ msg[0].addr = client->addr;
+ msg[0].flags = client->flags;
+ msg[0].len = 3;
+ msg[0].buf = (char *) &buf;
+
+ msg[1].addr = client->addr;
+ msg[1].flags = client->flags | I2C_M_RD;
+ msg[1].len = VZ89X_REG_MEASUREMENT_SIZE;
+ msg[1].buf = (char *) &data->buffer;
+
+ ret = i2c_transfer(client->adapter, msg, 2);
+
+ return (ret == VZ89X_REG_MEASUREMENT_SIZE) ? 0 : ret;
+}
+
static int vz89x_get_measurement(struct vz89x_data *data)
{
int ret;
- int i;
/* sensor can only be polled once a second max per datasheet */
if (!time_after(jiffies, data->last_update + HZ))
return 0;
- ret = i2c_smbus_write_word_data(data->client,
- VZ89X_REG_MEASUREMENT, 0);
+ ret = vz89x_i2c_xfer(data, VZ89X_REG_MEASUREMENT);
if (ret < 0)
return ret;
- for (i = 0; i < VZ89X_REG_MEASUREMENT_SIZE; i++) {
- ret = i2c_smbus_read_byte(data->client);
- if (ret < 0)
- return ret;
- data->buffer[i] = ret;
- }
-
ret = vz89x_measurement_is_valid(data);
if (ret)
return -EAGAIN;
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-iio" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
