diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 76e1f64..30af876 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -162,8 +162,8 @@
  *
  * as seen in the HID specification v1.11 6.2.2.7 Global Items.
  *
- * Only exponent 1 length units are processed. Centimeters are converted to
- * inches. Degrees are converted to radians.
+ * Only exponent 1 length units are processed. Centimeters and inches are
+ * converted to millimeters. Degrees are converted to radians.
  */
 static __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
 {
@@ -184,13 +184,16 @@
 	 */
 	if (code == ABS_X || code == ABS_Y || code == ABS_Z) {
 		if (field->unit == 0x11) {		/* If centimeters */
-			/* Convert to inches */
-			prev = logical_extents;
-			logical_extents *= 254;
-			if (logical_extents < prev)
+			/* Convert to millimeters */
+			unit_exponent += 1;
+		} else if (field->unit == 0x13) {	/* If inches */
+			/* Convert to millimeters */
+			prev = physical_extents;
+			physical_extents *= 254;
+			if (physical_extents < prev)
 				return 0;
-			unit_exponent += 2;
-		} else if (field->unit != 0x13) {	/* If not inches */
+			unit_exponent -= 1;
+		} else {
 			return 0;
 		}
 	} else if (code == ABS_RX || code == ABS_RY || code == ABS_RZ) {