iio: imu: inv_mpu6050: make loop a do-while

Martin Kelly · jic23 · commit cbf73ae59bee · 2018-05-12T10:01:41.000+01:00
Prior to this loop, we check if fifo_count &lt; bytes_per_datum and bail if
so. This means that when we hit the loop, we know that fifo_count &gt;=
bytes_per_datum, so the check is unneeded and we can turn the loop into
a do-while for a slight performance improvement.

Signed-off-by: Martin Kelly &lt;mkelly@xevo.com&gt;
Signed-off-by: Jonathan Cameron &lt;Jonathan.Cameron@huawei.com&gt;
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -175,7 +175,7 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 	if (kfifo_len(&st->timestamps) >
 	    fifo_count / bytes_per_datum + INV_MPU6050_TIME_STAMP_TOR)
 		goto flush_fifo;
-	while (fifo_count >= bytes_per_datum) {
+	do {
 		result = regmap_bulk_read(st->map, st->reg->fifo_r_w,
 					  data, bytes_per_datum);
 		if (result)
@@ -194,7 +194,7 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
 							   timestamp);
 
 		fifo_count -= bytes_per_datum;
-	}
+	} while (fifo_count >= bytes_per_datum);
 
 end_session:
 	mutex_unlock(&st->lock);
